Medusa Ransomware Group's Attack on Stone, Avant & Daniels

Medusa ransomware group claimed an attack on Stone, Avant & Daniels. The group obtained several pieces of corporate data, including financial documents, employees' data, PII documents, email correspondence, and confidential agreements. Stone, Avant & Daniels are certified public accountants and business consultants.

The Rise of Medusa RaaS

The Medusa is a RaaS that made its debut in the summer of 2021 and has evolved to be one of the more active RaaS platforms in late 2022, but attack volumes have been inconsistent in the first half of 2023. The attackers restart infected machines in safe mode to avoid detection by security software as well preventing recovery by deleting local backups, disabling startup recovery options, and deleting VSS Shadow Copies to thwart encryption rollback.

Attack Patterns and Ransom Demands

Medusa ramped up attacks in the latter part of 2022 and have been one of the more active groups in the first quarter of 2023 but appear to have waned somewhat in the second quarter. Medusa typically demands ransoms in the millions of dollars which can vary depending on the target organization’s ability to pay. The Medusa RaaS operation (not to be confused with the operators of the earlier MedusaLocker ransomware) typically compromises victim networks through malicious email attachments (macros), torrent websites, or through malicious ad libraries.

Technical Capabilities and Targets

Medusa can terminate over 280 Windows services and processes without command line arguments (there may be a Linux version as well, but it is unclear at this time.) Medusa targets multiple industry verticals, especially healthcare and pharmaceutical companies, and public sector organizations too.

Double Extortion Scheme

Medusa also employs a double extortion scheme where some data is exfiltrated prior to encryption, but they are not as generous with their affiliate attackers, only offering as much as 60% of the ransom if paid.