Summary Note: this joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.
The Federal Bureau of Investigation (FBI), the Cybersecurity and Infrastructure Security Agency (CISA), the Department of the Treasury, and the Financial Crimes Enforcement Network (FinCEN) are releasing this CSA to provide information on MedusaLocker ransomware. Observed as recently as May 2022, MedusaLocker actors predominantly rely on vulnerabilities in Remote Desktop Protocol (RDP) to access victims’ networks. The MedusaLocker actors encrypt the victim’s data and leave a ransom note with communication instructions in every folder containing an encrypted file. The note directs victims to provide ransomware payments to a specific Bitcoin wallet address. MedusaLocker
appears to operate as a Ransomware-as-a-Service (RaaS) model based on the observed split of ransom payments. Typical RaaS models involve the ransomware developer and various affiliates that deploy the ransomware on victim systems. MedusaLocker ransomware payments appear to be consistently split between the affiliate, who receives 55 to 60 percent of the ransom, and the developer, who receives the remainder.
Link to full CISA Bulletin: AA22-181A-#StopRansomware-TLP White.pdf