Internal Breach of 'The Gentlemen' Ransomware Group Exposes Infrastructure, Chats, and Victim Data
Not So Gentle: 'The Gentlemen' Ransomware Gang Hacked, Internal Operations Exposed
Impact Scope
People Affected
Over 1,570 victim organizations
Related Entities
Threat Actors
Organizations
Products & Tech
Other
Full Report
Executive Summary
In a case of profound irony, the ransomware-as-a-service (RaaS) group The Gentlemen has been hacked, leading to a massive leak of its internal data. The breach, analyzed by Check Point Research, has provided the cybersecurity community with a rare and detailed window into the inner workings of a modern ransomware operation. The leaked data includes internal affiliate chats, access to backend infrastructure and databases, and a victim list that is far larger than previously known. The findings detail the group's tactics, which include targeting internet-facing systems and using tools to disable EDR solutions. Despite this catastrophic operational security (OPSEC) failure, the group appears undeterred and is reportedly continuing its campaigns.
Threat Overview
The Gentlemen RaaS group, active since 2025, operates a typical affiliate-based model. They provide the malware, negotiation platform, and leak site, while their affiliates carry out the attacks. The group was known for offering a particularly generous revenue split, giving affiliates 90% of the ransom payments, which likely helped them attract a large number of partners.
Leaked TTPs
Analysis of the internal chats and data revealed the group's standard operating procedure:
- Initial Access: Primarily targeting internet-facing systems, likely through exploiting unpatched vulnerabilities or using compromised credentials. (
T1190 - Exploit Public-Facing Application) - Defense Evasion: Affiliates discussed and used tools specifically designed to disable or bypass endpoint detection and response (EDR) and antivirus solutions. (
T1562.001 - Disable or Modify Tools) - Credential Abuse: The group focused on credential abuse techniques for lateral movement and privilege escalation.
- Broad Impact: Their malware is capable of encrypting a wide range of environments, including Windows, Linux, NAS devices, and VMware ESXi servers, a common feature of modern, enterprise-targeting ransomware. (
T1486 - Data Encrypted for Impact)
Impact Assessment
The most significant revelation from the breach is the true scale of The Gentlemen's operations. While their public leak site listed a certain number of victims to create pressure, the internal database revealed a staggering 1,570+ victims. This highlights a crucial intelligence gap for defenders: the public face of a ransomware group may represent only a fraction of their actual impact. Many victims may be paying ransoms, restoring from backups, or are simply not deemed high-profile enough to be listed publicly.
The breach itself is a major blow to the group's credibility within the cybercriminal underground. Trust and OPSEC are paramount, and being hacked so thoroughly undermines their reputation. However, the fact that they are continuing operations, even partnering with a new version of the BreachForums hacking forum, shows the resilience and brazenness of these groups. The leaked data, while damaging to the criminals, provides invaluable intelligence for defenders and law enforcement.
Detection & Response
The TTPs revealed in the leak are common among many modern ransomware groups. Defenders can use this intelligence to hone their detection strategies.
Detection Strategies
- EDR Tampering Alerts: Configure EDR and AV solutions to send a high-priority, tamper-proof alert if their agent is stopped, disabled, or otherwise modified. This is a critical indicator of a hands-on-keyboard attack.
- ESXi Monitoring: For virtualized environments, monitor for unusual activity on ESXi management interfaces, such as the execution of shell commands, unexpected SSH sessions, or large-scale vMotion or snapshot deletion events.
- Internet-Facing System Hardening: Vigorously scan and patch all internet-facing systems. Any service exposed to the internet should be considered a potential entry point and must be fully patched and hardened.
Intelligence-Led Defense
Security teams should analyze the full list of victims, if it becomes available, to identify trends. Are they targeting specific industries, geographies, or technologies? This information can be used to perform proactive risk assessments and bolster defenses in relevant areas.
Mitigation Recommendations
Prevent Initial Access (
M1051 - Update Software):- The Gentlemen's focus on internet-facing systems reinforces the need for robust vulnerability and patch management. Prioritize patching for all edge devices, including VPNs, firewalls, and web servers.
Protect Security Tools (
M1025 - Privileged Process Integrity):- Deploy EDR and AV solutions that have strong anti-tampering features enabled. Access to manage these tools should be tightly controlled and require MFA.
Secure Virtual Infrastructure:
- Harden ESXi environments. Disable unused services, enforce complex passwords, use lockdown mode, and strictly limit access to management interfaces to a dedicated, segmented management network.
Backup and Recovery:
- Maintain offline, immutable backups of all critical systems, especially ESXi datastores. Regularly test your recovery process to ensure you can restore operations without paying a ransom.
Timeline of Events
MITRE ATT&CK Mitigations
Privileged Process Integrity
Deploying security tools with strong anti-tampering capabilities prevents attackers from carrying out the common TTP of disabling EDR before deploying ransomware.
Update Software
As the group targets internet-facing systems, a rigorous patch management program is the best defense against initial access.
Network Segmentation
Properly segmenting the network, especially isolating ESXi management interfaces, can prevent lateral movement and limit the blast radius of an attack.
Privileged Account Management
Strict control over privileged accounts makes it harder for attackers to move laterally and gain the permissions needed to deploy ransomware across the enterprise.
D3FEND Defensive Countermeasures
A key TTP for The Gentlemen and other ransomware groups is disabling security tools. To counter this, organizations must harden their endpoint security agents. Utilize EDR/AV solutions that have robust, kernel-level anti-tampering and self-protection mechanisms. These features should be enabled by default. Access to the EDR management console should be protected by MFA and restricted to a minimal number of security personnel. This ensures that even if an attacker gains administrative privileges on an endpoint, they cannot easily stop or uninstall the security agent, meaning it can continue to monitor, detect, and report on their subsequent malicious activity, such as the ransomware execution itself.
The report highlights that The Gentlemen targets ESXi servers, a common tactic for maximum impact. Hardening the virtualization platform is therefore critical. This includes: 1) Isolating the ESXi management network from all other networks, especially user subnets. 2) Disabling unused services on ESXi hosts, such as the SSH service, unless actively needed for administration. 3) Enforcing complex passwords and regular rotation for the ESXi root account. 4) Utilizing ESXi's 'Lockdown Mode' to restrict management access to only the vCenter Server. These steps significantly reduce the attack surface of the virtualization infrastructure, making it much harder for an attacker who has gained a foothold in the IT environment to pivot and encrypt the organization's most critical assets.
Given that The Gentlemen targets internet-facing systems, deploying honeypots that mimic these systems can be an effective early warning system. Set up decoy servers that appear to be vulnerable VPN gateways, RDP servers, or web applications. These decoys should have no production value and be heavily monitored. Any interaction with these systems is, by definition, malicious. An attacker attempting to brute-force credentials or exploit a vulnerability on a decoy server will trigger high-fidelity alerts, notifying the security team of an active threat targeting their perimeter long before legitimate systems are impacted. The intelligence gathered can be used to block the attacker's IP address and hunt for similar activity against real production assets.
Sources & References
Article Author
Jason Gomes
• Cybersecurity PractitionerCybersecurity professional with over 10 years of specialized experience in security operations, threat intelligence, incident response, and security automation. Expertise spans SOAR/XSOAR orchestration, threat intelligence platforms, SIEM/UEBA analytics, and building cyber fusion centers. Background includes technical enablement, solution architecture for enterprise and government clients, and implementing security automation workflows across IR, TIP, and SOC use cases.
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