Anthropic VS Code Extension on Cursor Backdoored for Nearly 12 Hours
It's still unknown how attackers gained access to Anthropic's verified Cursor account.
TL;DR
- An Anthropic VS Code extension on the Cursor marketplace was backdoored, version 2.1.313, affecting potentially 5,000 users.
- The compromised extension attempted to install a persistent SSH backdoor across Windows, macOS, and Linux.
- Capabilities of the backdoor included collecting host and user information and attempting to establish a reverse SSH tunnel.
- Bugs in the malicious code prevented the backdoor from fully functioning in some cases, but it still installed persistence and beaconed reconnaissance.
- Cursor removed the malicious version, blocked distribution, and temporarily shut down the VSCode Marketplace to audit security.
- Anthropic has not yet publicly warned its customers about the incident.