GoKawiilMalicious Claude Code extension spread through Cursor marketplace for 11 hours
Cursor, the SpaceX-owned AI coding platform, found a backdoored version of Anthropic's Claude Code extension in its marketplace for about 11 hours on Thursday, downloaded by up to 5,000 users across Windows, macOS and Linux. Cursor temporarily closed the marketplace, said no other extensions were affected, and published remediation steps. Anthropic confirmed its own systems and official distribution channels were not compromised, saying an attacker used access to Cursor's marketplace to publish a tampered copy.