Sanatorio Delta Ransomware Attack by thegentlemen (May 2026)

Claim Summary

On May 24, 2026, the ransomware group known as “thegentlemen” posted a claim on their dark web leak site alleging they have compromised Sanatorio Delta, a private healthcare institution based in Rosario, Argentina. According to the threat actor’s post, they claim to have exfiltrated data from the organization, though the volume of data allegedly stolen remains undisclosed. The group’s leak site entry includes a description of Sanatorio Delta as a provider with over 40 years of medical excellence, operating 10 modern facilities with 250+ professionals across 50+ specialties. This claim has not been independently verified by Yazoul Security or any third-party intelligence source.

Threat Actor Profile

The group operating under the moniker “thegentlemen” presents a concerning but poorly documented threat profile. Based on available intelligence, the group’s known toolset includes:

• DumpBrowserSecrets – for credential theft from browsers
• Hydra – for brute-force authentication attacks
• KslDump – for memory dumping and credential extraction
• EDRStartupHinder – to disable endpoint detection and response systems
• GFreeze and GLinker – likely custom tools for lateral movement or encryption
• ADFind and BloodHound – for Active Directory reconnaissance and privilege escalation

The group’s total known victim count is currently unknown, and no public research or YARA rules have been published for their specific ransomware variant. This lack of documented activity raises questions about their operational maturity. It is possible that “thegentlemen” is a rebranded or newly emerged group, or that this claim is an opportunistic exaggeration. Their toolset suggests a focus on initial access via credential theft and Active Directory exploitation, which aligns with common ransomware tactics.

Alleged Data Exposure

The threat actor claims to have accessed data from Sanatorio Delta, but has not provided specific details about the types of records allegedly compromised. Based on the organization’s description as a healthcare provider, potential data exposure could include:

• Patient medical records and treatment histories
• Personally identifiable information (PII) such as names, addresses, and identification numbers
• Insurance and billing information
• Employee credentials and internal communications
• Operational data from 10 facilities across 50+ specialties

Without a data sample or volume disclosure, the credibility of this claim remains low. Ransomware groups frequently exaggerate or fabricate data theft to pressure victims into payment.

Potential Impact

If the claim is verified, the impact on Sanatorio Delta could be severe:

• Patient Trust: Exposure of medical records could undermine patient confidence in the institution’s data security practices.
• Regulatory Consequences: Argentina’s Personal Data Protection Law (Law 25.326) requires notification of data breaches involving sensitive health information, potentially leading to fines or legal action.
• Operational Disruption: The group’s use of EDRStartupHinder suggests they may have attempted to disable security controls, which could indicate broader system compromise beyond data theft.
• Reputational Damage: As a 40-year-old institution, a public breach could harm long-standing community relationships.

What to Watch For

• Leak Site Updates: Monitor thegentlemen’s leak site for any posted data samples, which would confirm the claim’s validity.
• Official Statements: Sanatorio Delta may issue a public statement or regulatory filing if the breach is confirmed.
• Indicators of Compromise: Security teams should watch for thegentlemen’s known tools (e.g., ADFind, BloodHound, KslDump) in network logs.
• Phishing Campaigns: Stolen patient data could be used in targeted phishing attacks against individuals.

For further guidance, refer to Yazoul Security’s ransomware advisory at /advisory/ransomware-preparedness/ and our threat intelligence portal at /intel/ransomware-groups/.

Disclaimer

This report is based on unverified claims made by the ransomware group “thegentlemen” on their dark web leak site. Yazoul Security has not independently confirmed the compromise of Sanatorio Delta, the exfiltration of data, or the accuracy of any information provided by the threat actor. Ransomware groups routinely fabricate or exaggerate claims to pressure victims. This intelligence is provided for situational awareness only and should not be used as a basis for action without further verification. Organizations should contact Sanatorio Delta directly for official confirmation.