Official Claude Code Extension on Cursor Marketplace Trojanized with Persistent SSH Backdoor

Cybersecurity researchers disclosed that a trojanized version of Anthropic's official Claude Code extension was distributed through the Cursor Marketplace as a legitimate update, attempting to install a persistent SSH backdoor on affected systems. The malicious update, version 2.1.313, was published under the extension's legitimate publisher identity, prompting Cursor to temporarily shut down the marketplace.