Trojanized Claude Code extension exposed thousands of developer machines to persistent access

A malicious Claude Code extension distributed through Cursor’s Open VSX-based marketplace ran when activated and attempted to establish SSH access, persistence and an attacker-controlled connection. Cursor removed the package, rebuilt its marketplace and disabled the server, but those actions do not clean affected machines. The source estimates that up to 5,000 users may have been exposed and says the compromise route remains unknown. Users of version 2.1.313 need remediation, credential rotation and endpoint review.












