Cursor Marketplace Hosts Malicious Claude Code Extension
Original title: Malicious Claude Code Extension Served in Cursor Supply Chain Attack
Versions 2.1.312 and 2.1.313 of Anthropic's Claude Code extension were maliciously published for 11 hours targeting macOS and Windows users.
A malicious actor published tampered versions of the Claude Code extension to the Cursor VS Code Extension Marketplace for roughly 11 hours. The extension contained JavaScript that established a reverse SSH tunnel upon loading. Approximately 5,000 developers may have installed the compromised versions. Cursor removed the malicious extensions, rotated keys, and rebuilt the marketplace. Anthropic updated its legitimate extension to version 2.1.314.
Unconfirmed: Anthropic found no evidence of other versions or official distributions being affected.
- Malicious versions live for 11 hours
- Extension installs SSH key and reverse tunnel
- Failed due to missing admin rights
- 5,000 developer systems impacted
- Cursor suspended marketplace
Impact: remote code execution via SSH tunnel
- 1.Uninstall malicious extension versions
- 2.Remove unauthorized SSH key
- 3.Rebuild and reopen marketplace
- Products
- claude-code extension
From the original article
2 min read at securityweek.com
The extension performed host reconnaissance and attempted to create a reverse SSH tunnel. The post Malicious Claude Code Extension Served in Cursor Supply Chain Attack appeared first on SecurityWeek.
By Ionut Arghire · securityweek.com
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