MedusaLocker Ransomware is a ransomware operation attributed to eCrime (RaaS), active since 2019. Persistent RaaS targeting healthcare and education. Key capabilities include: AES-256+RSA, .encrypted extension, RDP brute force initial access.
Overview & Operations
Persistent RaaS targeting healthcare and education. The group has been active since 2019 and operates as part of the broader ransomware-as-a-service ecosystem. Notable technical characteristics include: AES-256+RSA, .encrypted extension, RDP brute force initial access.
MedusaLocker Ransomware employs double extortion tactics — encrypting victim data while simultaneously exfiltrating sensitive information for leverage. Organizations that refuse to pay face public data exposure on the group's leak site.
- Operator: eCrime (RaaS)
- Active since: 2019
- Tooling: AES-256+RSA, .encrypted extension, RDP brute force initial access
- Extortion model: Double extortion (encryption + data leak)
Tactics, Techniques & Procedures
MedusaLocker operators typically gain initial access through phishing, exploiting public-facing applications (VPN, RDP, Exchange), or purchasing access from initial access brokers (IABs). Post-compromise, they deploy Cobalt Strike or similar C2 frameworks for lateral movement before deploying the ransomware payload.
- Initial access: Phishing, vulnerability exploitation, RDP brute force, IAB purchases T1566.001 T1190
- Execution: PowerShell, WMI, PsExec for payload deployment T1059.001
- Persistence: Scheduled tasks, service creation, registry modifications T1053.005
- Defense evasion: Security tool tampering, Safe Mode exploitation, BYOVD T1562.001
- Lateral movement: RDP, SMB, WMI, admin shares T1021.002
- Exfiltration: Custom exfiltration tools, cloud storage, Rclone T1567
- Impact: File encryption with custom encryptor T1486
MITRE ATT&CK Mapping
| Tactic | Technique | Usage |
|---|---|---|
| Initial Access | T1190 Exploit Public-Facing App | VPN/RDP/Exchange exploitation |
| Execution | T1059.001 PowerShell | Post-exploitation scripting |
| Persistence | T1053.005 Scheduled Task | Persistence mechanism |
| Defense Evasion | T1562.001 Disable Security Tools | EDR/AV tampering |
| Credential Access | T1003.001 LSASS Memory | Credential dumping |
| Lateral Movement | T1021.002 SMB/Admin Shares | Network propagation |
| Exfiltration | T1567 Exfil Over Web Service | Data theft before encryption |
| Impact | T1486 Data Encrypted for Impact | Ransomware deployment |
Detection & Defense
- Backup strategy: Maintain offline, immutable backups with tested restoration procedures
- Network segmentation: Limit lateral movement paths between critical systems
- EDR deployment: Behavioral detection for ransomware indicators (mass file modification, shadow copy deletion)
- MFA enforcement: Protect RDP, VPN, and admin portals with phishing-resistant MFA
- Patch management: Prioritize VPN, Exchange, and remote access vulnerabilities
- Threat intelligence: Monitor for MedusaLocker IOCs and dark web activity
Protect Against MedusaLocker Ransomware
Mjolnir Security provides ransomware prevention, detection, and response services against MedusaLocker Ransomware and similar threats.
- Ransomware Readiness Assessment Evaluate your organization's resilience against MedusaLocker and similar ransomware operations with gap analysis and remediation recommendations.
- Ransomware Incident Response Rapid containment, negotiation support, and forensic investigation when ransomware strikes.
- 24/7 Incident Response Rapid containment and forensic investigation. Call +1 833 403 5875.
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