Cursor Says Malicious Anthropic.claude-code 2.1.312 and 2.1.313 Reach Its Marketplace

Cursor says attackers published modified Anthropic.claude-code 2.1.312 and 2.1.313 in its VS Code Extension Marketplace for about 11 hours on Oct. 29, 2026, carrying code that tried to add an SSH key labeled svc-telemetry and open a reverse tunnel. Cursor removed the versions, shut the marketplace, and took the attacker server offline.

• Cursor says the modified extension collects hostname, username, OS, Git email and public IP from affected machines.
• Cursor says the backdoor step fails on most hosts because enabling local SSH requires administrator rights.
• Cursor warns uninstalling the extension may not be enough because the payload drops standalone persistence scripts.