Every morning, security people around the world face the same ritual: opening their vulnerability feed to find a lot of new CVE entries that appeared overnight. Over the past decade, this flood has become a defining challenge of modern defensive security. Some numbers[1]:
Introduction
This diary provides indicators from a Lumma Stealer infection that was followed by Sectop RAT (ArechClient2). I searched for cracked versions of popular copyright-protected software, and I downloaded the initial malware after following the results of one such search. This is a common distribution technique for various families of malware, and I often find Lumma Stealer this way.
In this case, the initial malware for Lumma Stealer was delivered as a password-protected 7-zip archive. The extracted malware is an inflated Windows executable (EXE) file at 806 MB. The EXE is padded with null-bytes (0x00), a technical which increases the EXE size while allowing the compressed archive file to be much smaller. The password-protected archive and inflated EXE file are designed to avoid detection.
Images from the infection
Shown above: Example of a page with instructions to download the initial malware file.
Shown above: Traffic from the infection filtered in Wireshark.
Shown above: Sectop RAT persistent on an infected Windows host.
Indicators of Compromise
Example of download link from the site advertising cracked versions of copyright-protected software:
hxxps[:]//incolorand[.]com/how-visual-patch-enhances-ui-consistency-across-releases/?utm_source={CID}&utm_term=Adobe%20Premiere%20Pro%20(2026)%20Full%20v26.0.2%20Espa%C3%B1ol%20[Mega]&utm_content={SUBID1}&utm_medium={SUBID2}
Example of URL for page with the file download instructions:
hxxps[:]//mega-nz.goldeneagletransport[.]com/Adobe_Premiere_Pro_%282026%29_Full_v26.0.2_Espa%C3%B1ol_%5BMega%5D.zip?c=ABUZ4WkRgQUA_YUCAFVTFwASAAAAAACh&s=360721
Example of URL for file download from site above site impersonating MEGA:
hxxps[:]//arch.primedatahost3[.]cfd/auth/media/JvWcFd5vUoYTrImvtWQAASTh/Adobe_Premiere_Pro_(2026)_Full_v26.0.2_Espa%C3%B1ol_%5BMega%5D.zip
Downloaded file:
Extracted malware:
Deflated malware:
Lumma Stealer command and control (C2) domains from Triage sandbox analysis:
Follow-up malware:
Example of Sectop RAT C2 traffic from an infected Windows host:
—
Bradley Duncan
brad [at] malware-traffic-analysis.net
(c) SANS Internet Storm Center. https://isc.sans.edu Creative Commons Attribution-Noncommercial 3.0 United States License.
Starting March 10, 2026, my DShield sensor started getting probe for various AI models such as claude, openclaw, huggingface, etc. Reviewing the data already reported by other DShield sensors to ISC, the DShield database shows reporting of these probes started that day and has been active ever since.
Last week, I wrote about attackers scanning for various webshells, hoping to find some that do not require authentication or others that use well-known credentials. But some attackers are paying attention and are deploying webshells with more difficult-to-guess credentials. Today, I noticed some scans for what appears to be the "EncystPHP" web shell. Fortinet wrote about this webshell back in January. It appears to be a favorite among attackers compromising vulnerable FreePBX systems.
I spotted an interesting piece of JavaScript code that was delivered via a phishing email in a RAR archive. The file was called “cbmjlzan.JS” (SHA256:a8ba9ba93b4509a86e3d7dd40fd0652c2743e32277760c5f7942b788b74c5285) and is only identified as malicious by 15 AV’s on VirusTotal[1].
In a previous diary [1], we looked to see how numbers were used within passwords submitted to honeypots. One of the items of interest was how dates, and more specifically years, were represented within the data and how that changed over time. It is often seen that years and seasons are used in passwords, especially when password change requirements include frequenty password changes. Some examples we might see today:
This is the seventh update to the TeamPCP supply chain campaign threat intelligence report, "When the Security Scanner Became the Weapon" (v3.0, March 25, 2026). Update 006 covered developments through April 3, including the CERT-EU European Commission breach disclosure, ShinyHunters' confirmation of credential sharing, Sportradar breach details, and Mandiant's quantification of 1,000+ compromised SaaS environments. This update consolidates five days of intelligence from April 3 through April 8, 2026.
One question that often comes up when I talk about honeypots: Are attackers able to figure out if they are connected to a honeypot? The answer is pretty simple: Yes!
Most "medium interaction" honeypots, like the one we are using, are just simulating various systems. These simulations are incomplete. For example, we are using the "Cowrie" honeypot to emulate SSH and telnet servers. Once an attacker is connected, any package they are installing will appear to install. In the past, I have written about attackers attempting to install bogus packages. If the install appears to succeed, the attacker knows they are connected to a honeypot. Some attackers look for SSH artifacts, such as the number and types of ciphers supported by SSH.
Today, I noticed one attacker, (IP address %%ip:45.135.194.48%%), using another common trick: Cowrie will often allow attackers to connect "randomly". The effect is that various username and password combinations appear to work. In this case, the attacker used usernames and passwords that are highly unlikely to work. If they succeed, they know they are connected to a honeypot. Here are some of the usernames and passwords used:
| username | password |
|---|---|
| admin | definitely_not_valid_creds |
| honeypot | indexer |
| honeypotter | imaginegettingindexed |
| xXhoneypotXx | P@ssw0rd1337! |
| youjustgotindexed | getindexedretard |
Will we do anything to block these types of requests? Maybe… I am not sure it is important enough to "hide" honeypots. One advantage we have is that many of our honeypots are connected to home networks with dynamic IPs. As a result, any IP address list an attacker will create is somewhat ephemeral. Secondly, we are mostly interested in internet-wide scans. We are not going to detect targeted attacks or zero days.
—
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.
Webshells remain a popular method for attackers to maintain persistence on a compromised web server. Many "arbitrary file write" and "remote code execution" vulnerabilities are used to drop small files on systems for later execution of additional payloads. The names of these files keep changing and are often chosen to "fit in" with other files. Webshells themselves are also often used by parasitic attacks to compromise a server. Sadly (?), attackers are not always selecting good passwords either. In some cases, webshells come with pre-set backdoor credentials, which may be overlooked by a less sophisticated attacker.
![[Guest Diary] Compromised DVRs and Finding Them in the Wild, (Thu, Apr 16th)](https://www.ironcastle.net/wp-content/uploads/2026/04/status-8.gif)
