Malicious Version of Claude Code Extension Appears in Cursor Marketplace, Affecting Up to 5,000 Users

October 30: Cursor said in a post on X that a maliciously tampered Claude Code VS Code extension (version 2.1.313) appeared in its extension marketplace, affecting up to 5,000 users; the version was not developed by Anthropic. According to Cursor's security advisory, the malicious extension collects user host information and attempts to plant an SSH backdoor. Cursor has taken the extension down and recommends that users update the Claude Code extension to version 2.1.314.