Anthropic got compromised.
Their Claude Code extension on Visual Studio has malware in it, which creates a remote access Trojan to desktops.
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C2 server collected for each victim endpoint:
- hostname
- username
- OS
- architecture
- home directory path
- environment variable names
- working directories
- configured Git email
It then ran a reverse SSH connection allowing the threat actor to pick and chose which victims to have hands on keyboard access to.
I'm confirmed the new, replacement versions Anthropic published overnight (which auto update) do *not* remove the prior backdoors and recon activity. So SSH still reverse calls out etc, you need to manually remediate every impacted VSCode and Cursor system.
Anthropic *must* tell customers what happened in a completely transparent way.
I've confirmed Binance use Claude Code with this extension.
That extension has 29 million installs, one of the most popular extensions in DevOps. It creates a reverse SSH backdoor.
Anthropic silently removed the backdoor 7 hours ago and hasn’t disclosed a security incident.
The plugin auto updates so every org will have been impacted.
To be clear this is a supply chain attack, the threat actor got reverse SSH (command line) connectivity to Anthropic customer environments at scale.
FWIW the compromised version, 2.1.313, was removed from OpenVSX. 2.1.314 is the ‘fixed’ version.
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Anthropic's Claude Code Cursor extension was also compromised, same remote access backdoor https://cursor.com/blog/claude-code-extension-security-notice
Anthropic still haven't admitted what has happened.
@GossiTheDog here's a detection #osquery for #macos, in case it helps anyone
https://gist.github.com/RichardoC/9753dfa5aeffc6a1201f5e57114f54ff
#compromisedVScodeExtension
#claude
#detection
detect-compromised-claude-vscode-extension-macos-2026-10-26