1HarnessesA backdoored Claude Code extension sat in Cursor's marketplace for 11 hours
ExpandCollapse
A backdoored Claude Code extension sat in Cursor's marketplace for 11 hours
ExpandCollapseIf you installed Claude Code 2.1.312 or 2.1.313 through Cursor on 29 October, check your SSH keys today.
The detail Cursor says at most 5,000 users were affected, on macOS and Windows, between 2:27am and 1:35pm PT. The payload added an attacker key, set up persistence and sent host details out.
The catch Cursor has not said how a tampered build was published under Anthropic's name. Anthropic says its own channels were never affected.
Worth learning the supply-chain attack. You trust a package because of where it comes from, so an attacker who controls the distribution channel inherits that trust without touching the original code.