Malicious Claude Code extension with SSH backdoor was live on Cursor marketplace for 11 hours
MALWAREAnthropicredteam/daily · 2 sources
- Severity
- High
- Sources
- 2
What happened
For about 11 hours on 29 October 2026, fake versions of a popular AI coding helper extension were available in Cursor's extension store. They were designed to give attackers a hidden way into affected Windows and Mac computers. Cursor has removed them, shut down the attacker's server and says the official version was not affected.
Like I’m new · Written by AI from 2 sources · Wrong?
What to do
- Check whether Anthropic.claude-code versions 2.1.312 or 2.1.313 are installed and remove them.
- Inspect authorised SSH keys for an entry labelled svc-telemetry and remove it if found.
- Review extension installation records, endpoint alerts and network logs for the indicators Cursor published.
- Isolate affected hosts where payload execution or backdoor installation is evident, then rotate accessible credentials and sessions from a trusted system.
Written by AI from the sources, checked against them
Full story timeline · 2 updates
Who reported · 2 outlets
Cyber Security NewsCSO Online
Who and what is in it
Products