Anthropic reportedly hacked to deliver remote access malware via Claude Code
- Status
- Corroborated, not yet confirmed by the vendor
- Kind
- Malicious package
- Vendor
- Anthropic
- Product
- Claude Code (VS Code extension)
- First seen
Summary
Security researcher Kevin Beaumont alleges that Anthropic was hacked so that Claude Code delivers remote access malware to millions of endpoints. The text provided does not include an official statement from Anthropic confirming the compromise.
If you use Anthropic
Check whether Claude Code is installed on your endpoints and identify the installed version
Scan affected machines for remote access malware and review recent Claude Code updates
Follow Anthropic's official security advisories before trusting or reinstalling Claude Code
Rotate credentials that were used on systems where Claude Code ran if compromise is confirmed
Check whether the Claude Code extension is installed and remove it if it came from Open VSX or Cursor Marketplace during the affected window
Inspect affected hosts for unexpected SSH keys, authorized_keys entries, and persistence mechanisms
What the sources say 24
· Mastodon: “A trojanized `anthropic.claude-code@2.1.313` artifact on Open VSX contained a malicious loader that could establish persistent remote access.” Source
· Mastodon: “A malicious anthropic.claude-code@2.1.313 artifact on Open VSX hid a 66-line loader ahead of the legitimate extension code.” Source
· Hacker News: “Official Claude Code extension compromise” Source
· The Hacker News: “Cybersecurity researchers have disclosed that the official Anthropic Claude Code extension was compromised on the Open VSX registry to install a persistent SSH backdoor on infected hosts.” Source
· Bluesky: “Their VS Code plugin had malware (ssh backdoor/trojan).” Source
· Kevin Beaumont on Bluesky: “New by me - Anthropic have been hacked to deliver remote access malware to millions of endpoints who use Claude Code.” Source
· Hacker News: “Anthropic hacked to deliver remote access trojan to Claude developer laptops” Source
· Bluesky: “The vscode, cursor and open-vsx extensions had malware in it.” Source
· r/cybersecurity: “Official Claude Code Extension on Cursor Marketplace Trojanized with Persistent SSH Backdoor” Source
· r/sysadmin: “This seems to be not widely reported yet but it certainly looks like Anthropic had a compromise somewhere that allowed an attacker to push malware into their VS Code and Cursor extensions.” Source
· r/cybersecurity: “On October 30, 2026, OpenSourceMalware published an analysis of a malicious build of the <code>anthropic.claude-code extension</code>, version 2.1.313, found on Open VSX.” Source
· oss-security: “Non-OSS: Claude Code for VS Code extension compromised” Source
· oss-security: “Re: Non-OSS: Claude Code for VS Code extension compromised” Source
· Mastodon: “Official # Claude Code # VSCode # extension # Compromised to Install Persistent # SSH # Backdoor” Source
· r/netsec: “Claude vs Code Extension compromised” Source
· Mastodon: “Researchers have identified a malicious version of the official Claude Code extension circulating on the Cursor Marketplace.” Source
· Mastodon: “A tampered Claude Code extension, version 2.1.313, was live in Cursor's marketplace for about 11 hours and reached up to 5,000 users.” Source
· Bluesky: “Claude Code extension on VS Code and Cursor has malware in it, creates a remote access Trojan to desktops.” Source
· Bluesky: “a version of the Claude Code extension for Visual Studio Code published on Cursor's marketplace contained a...” Source
· Mastodon: “Anthropic hacked to deliver remote access trojan” Source
· Mastodon: “Backdoors in official Claude Code extensions” Source
· Mastodon: “A Supply Chain Attack Put Malicious Anthropic Claude Extensions on Thousands of Devices” Source
· Mastodon: “Una versione malevola dell'estensione ufficiale Claude ha infettato fino a 5.000 sviluppatori, tentando di installare un backdoor SSH persistente.” Source
· Mastodon: “Official Claude Code extension compromise” Source