Gentlemen Ransomware: The Double Extortion Threat Targeting Manufacturing and Healthcare

   A New Threat Behind a Polished Name

Despite its refined name, there’s nothing courteous about Gentlemen ransomware. According to new research published by the AhnLab Security Emergency response Center (ASEC), this emerging threat group was first identified in August 2025 and has wasted no time establishing itself as one of the most aggressive and technically sophisticated ransomware operations of the year. Within just a few months of appearing on the scene, Gentlemen has executed successful attacks across at least 17 countries, demonstrating both ambition and capability that should concern businesses of all types.

What makes Gentlemen particularly dangerous is their operational approach. The group employs a double extortion model – meaning they don’t just encrypt your files and demand payment. They first infiltrate your network, steal your sensitive data, and then encrypt everything. If you refuse to pay, they threaten to publish your confidential information on dark web forums and hacking communities. It’s a one-two punch that leaves victims with few good options.

   Understanding the Severity

Most emerging ransomware groups take months to refine their operations and build momentum. Gentlemen arrived fully formed, executing coordinated attacks across multiple continents within weeks of their first appearance. This level of operational maturity from day one suggests either significant prior experience or access to resources most startup criminal enterprises simply don’t have.

The scope of Gentlemen’s operations in such a short timeframe is genuinely alarming for small and medium-sized businesses concerned about cybersecurity.

• Global reach confirmed in 17+ countries spanning Asia-Pacific, North America, South America, and the Middle East
• Multiple industries under attack including manufacturing, construction, healthcare, and insurance sectors
• Ranked among the most active emerging ransomware groups of 2025 according to multiple security researchers
• 16 confirmed industrial sector incidents in Q3 2025 alone, with one of the highest concentrations of industrial victims among new ransomware groups
• Double extortion tactics multiply the pressure on victims through both encryption and data theft threats
• No clear RaaS model yet identified, suggesting a potentially well-funded, centralized operation

Security researchers continue to investigate whether Gentlemen represents a rebranding of an existing group or an entirely new operation. Either way, the group’s rapid expansion and technical sophistication suggest they’re not amateurs – and they’re not going away anytime soon.

(Desktop After Encryption – Source: ASEC)

   How Gentlemen Attacks Work

What separates Gentlemen from opportunistic ransomware is their methodical approach. Every technical decision – from the password-protected payload to the targeted termination of backup services – reflects careful planning. These attackers know exactly what they’re doing and have built their tools to maximize damage while minimizing detection.

The technical implementation of Gentlemen ransomware reveals a well-engineered threat designed to maximize damage while evading detection. Understanding their methods is the first step toward effective network security.

Initial Access and Preparation:

• Attackers breach corporate networks using techniques common to advanced ransomware groups
• Group Policy Objects (GPO) manipulation spreads the infection across networked systems
• Bring Your Own Vulnerable Driver (BYOVD) techniques help bypass security software
• Windows Defender gets disabled early in the attack chain
• Backup services like Veeam are stopped to prevent recovery
• Database services including MSSQL and MongoDB are terminated
• System logs and traces are deleted to cover their tracks

The Encryption Process:

• Built using the Go programming language for cross-platform effectiveness
• Requires a specific password parameter to execute, preventing analysis in sandbox environments
• Uses X25519 elliptic curve cryptography combined with XChaCha20 stream cipher
• Generates unique encryption keys for each file, making bulk decryption nearly impossible
• Large files undergo partial encryption to speed up the attack while still rendering files unusable
• Encrypted files cannot be recovered without the attacker’s private key – there’s no workaround

The Extortion Phase:

• Ransom notes appear in all affected directories as “README-GENTLEMEN.txt”
• Desktop backgrounds change to display infection warnings
• Attackers claim full control of the network to maximize psychological pressure
• Stolen data is threatened for release on dark web forums
• Two sample files are offered for free decryption to “prove” they can restore access

The encryption structure is particularly nasty. By combining ECDH key exchange with XChaCha20 encryption and generating temporary keys that aren’t stored anywhere, the group has created a system where decryption is mathematically impossible without paying.

(Gentlemen Data Leak Site – Source: ASEC)

   Who’s Behind Gentlemen?

Attribution in ransomware investigations is notoriously difficult, and Gentlemen is no exception. The group has maintained strong operational security, leaving few breadcrumbs for researchers to follow. What we can determine comes primarily from analyzing their tactics, targets, and technical choices.

The attribution question remains open. Security researchers haven’t definitively connected Gentlemen to any known threat actors or established ransomware operations.

• No confirmed Ransomware-as-a-Service (RaaS) model has been identified, which is unusual for groups operating at this scale
• Unknown if they’re a rebrand of an existing group or a splinter operation from a larger outfit
• Operational sophistication suggests experience – these aren’t first-time attackers
• Primary targets are medium-to-large organizations, indicating strategic victim selection rather than opportunistic attacks
• Rapid global expansion points to significant resources and coordination capabilities

The password-protected execution model is particularly telling. This isn’t ransomware designed to spread randomly. Gentlemen operators appear to carefully select and compromise their targets before deploying the encryption payload, suggesting a hands-on-keyboard approach typical of more experienced cybercriminal operations.

   Who’s at Risk?

The uncomfortable truth is that Gentlemen’s target profile matches a significant portion of Houston’s business community. Manufacturing, healthcare, construction, and insurance represent major economic drivers in our region, and each has already appeared on Gentlemen’s victim list elsewhere in the world.

Based on confirmed attack patterns, certain organizations face elevated risk from Gentlemen ransomware campaigns. Houston-area businesses in these sectors should be especially vigilant about their IT support and security posture.

High-Risk Industries:

• Manufacturing operations (highest concentration of victims)
• Healthcare facilities and medical practices
• Construction companies
• Insurance providers
• Any organization with significant data assets worth stealing

Risk Factors:

• Medium-to-large organizations appear to be primary targets
• Companies with complex network infrastructures face greater exposure
• Organizations relying on Windows environments and Active Directory
• Businesses using Veeam backup solutions (specifically targeted for disruption)
• Companies running MSSQL or MongoDB databases
• Organizations without robust endpoint detection capabilities

Geographic Exposure:

• Attacks confirmed across North America, including the United States
• No evidence suggesting any region is “safe” from targeting
• Houston’s diverse economy – spanning energy, healthcare, manufacturing, and construction – places local businesses squarely in the threat profile

Small business IT support near me isn’t just a search term anymore – it’s a critical need. Even if you’re not a Fortune 500 company, being part of a supply chain that serves larger organizations can make you an attractive target.

(Ransom note (README-GENTLEMEN.txt)

   Protection and Remediation Steps

Prevention remains the best medicine, but realistic security planning also accounts for the possibility that prevention fails. Organizations need both strong perimeter defenses and the detection capabilities to catch attackers who slip through. Gentlemen’s multi-stage attack pattern actually creates multiple opportunities to detect and stop an intrusion before encryption begins.

Defending against Gentlemen requires a layered approach to cybersecurity that addresses both prevention and response capabilities.

Immediate Protective Measures:

• Ensure Windows Defender and endpoint protection remain active and updated
• Implement application whitelisting to prevent unauthorized executables
• Monitor for BYOVD attack indicators and block known vulnerable drivers
• Audit Group Policy Objects regularly for unauthorized modifications
• Segment networks to limit lateral movement capabilities
• Maintain offline backups that can’t be reached through network connections

Detection and Response:

• Deploy endpoint detection and response (EDR) solutions capable of identifying ransomware behaviors
• Monitor for suspicious PowerShell activity and volume enumeration
• Watch for attempts to stop backup and database services
• Implement 24/7 security monitoring where possible
• Establish incident response procedures before you need them
• Test backup restoration procedures regularly

Recovery Preparations:

• Maintain air-gapped backups updated on a regular schedule
• Document all critical systems and recovery procedures
• Establish relationships with cybersecurity incident response providers
• Consider cyber insurance that covers ransomware incidents
• Train staff on recognizing phishing and social engineering attempts

There’s no silver bullet here. Effective defense requires combining multiple computer security solutions into a cohesive strategy.

  How CinchOps Can Help

For Houston and Katy businesses concerned about emerging threats like Gentlemen ransomware, CinchOps provides the managed IT support and cybersecurity expertise needed to stay protected. We understand that small and medium-sized businesses face the same threats as larger enterprises but often lack dedicated security teams to address them.

• Comprehensive security assessments to identify vulnerabilities before attackers do
• Managed endpoint protection with continuous monitoring and rapid response capabilities
• Backup solutions designed for ransomware resilience, including air-gapped and immutable backup strategies
• Network security implementation including proper segmentation and access controls
• 24/7 monitoring services to detect suspicious activity when it happens
• Incident response planning so you’re prepared if an attack occurs
• Employee security training to reduce the human factor in successful attacks
• Regular vulnerability scanning and patch management to close security gaps

Don’t wait until you’re reading a ransom note to think about cybersecurity near me. CinchOps serves as your managed services provider partner, bringing enterprise-grade protection to Houston-area businesses at a price point that makes sense.

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For Additional Information on this topic: Threats Behind the Mask of Gentlemen Ransomware

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