Backdoors in official Claude Code extensions
cyberplace.social641 points by dsr_ 4 hours ago
641 points by dsr_ 4 hours ago
Cursor has released a security notice:
https://cursor.com/blog/claude-code-extension-security-notic...
Edit: related https://news.ycombinator.com/item?id=50301983
Looks like a solid response with instructions and scripts how to get rid of the infection, but it doesn’t explain how it got there.
Agreed, it doesn't offer a root cause analysis. Remedies are good but how do you prove that it won't happen again? Remember that these are never singular incidents but part of a bad security culture.
> Cursor: "This malicious version of the extension was not developed by Anthropic."
Wtf does that mean.
Given they mentioned taking down and rebuilding the marketplace registry in that post, it seems equally likely that Cursor’s infrastructure was the source of the intrusion and a folks are jumping the gun on attribution.
Edit: I was correct. https://news.ycombinator.com/item?id=50304129
It sounds to me like they're saying it wasn't an Anthropic employee which decided to drop an SSH backdoor.
I would guess it’s supposed to communicate a few things. One big one is, ”Our AI software factory didn’t do it. Don’t worry, letting Claude spin away with limited human supervision is still safe.”
someone got access to the account that can publish extension on cursor marketplace?
It means that Anthropic did not intentionally develop a malicious version, obviously. But it’s a bit disingenuous and tries to suggest that it wasn’t Anthropic that uploaded it and/or wasn’t published under Anthropic’s name, which isn’t true.
It would be hilarious if that’s an obfuscated way to say Claude developed it. “Claude, who was birthed but not hired by Anthropic, went rogue by hijacking the extension”
> Related posts: Cursor earns AIUC-1 certification for agent security and reliability
The irony.
These days no one is immune to these kind of attacks... Honestly it will only get worse from here.