Kevin Beaumont
@GossiTheDog@cyberplace.social
FWIW the compromised version, 2.1.313, was removed from OpenVSX. 2.1.314 is the ‘fixed’ version.
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Kevin Beaumont
@GossiTheDog@cyberplace.social
Anthropic's Claude Code Cursor extension was also compromised, same remote access backdoor https://cursor.com/blog/claude-code-extension-security-notice
Anthropic still haven't admitted what has happened.
Cursor
Security notice — malicious version of Anthropic.claude-code (2.1.313) identified in the Cursor Extension Marketplace · Cursor
Today we identified a security incident involving a specific extension package in the Cursor VS Code extension Marketplace: Anthropic.claude-code version 2.1.313.
Kevin Beaumont
@GossiTheDog@cyberplace.social
I've written a blog - Anthropic have been hacked to deliver remote access malware to millions of endpoints where developers use Claude Code.
Kevin Beaumont
@GossiTheDog@cyberplace.social
Threat actor's C2 server is now offline.
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Kevin Beaumont
@GossiTheDog@cyberplace.social
C2 server collected for each victim endpoint:
- hostname
- username
- OS
- architecture
- home directory path
- environment variable names
- working directories
- configured Git email
It then ran a reverse SSH connection allowing the threat actor to pick and chose which victims to have hands on keyboard access to.
Kevin Beaumont
@GossiTheDog@cyberplace.social
I'm confirmed the new, replacement versions Anthropic published overnight (which auto update) do *not* remove the prior backdoors and recon activity. So SSH still reverse calls out etc, you need to manually remediate every impacted VSCode and Cursor system.
Anthropic *must* tell customers what happened in a completely transparent way.