Trojanized Claude Code extension on Open VSX installs persistent SSH backdoor on developer machines
MALWAREAnthropicredteam/daily · 2 sources
- Severity
- High
- Sources
- 2
What happened
The trojanized artifact is anthropic.claude-code 2.1.313 from Open VSX, with 66 lines of JavaScript injected into the legitimate bundle so the attacker's script executes before the extension's own code and establishes persistent SSH access. The Hacker News reports the root cause as a compromise of the Cursor Marketplace, which Cursor briefly took offline to remove the malware. The articles give no CVE ID, attribution or indicators of compromise. Defenders should check developer systems for this extension version and review them for unauthorised SSH access, though the articles do not detail specific remediation steps.
For security analysts · Written by AI from 2 sources · Wrong?
What to do
- Keep devices updated and install software only from official stores or the maker’s site.
General advice for this kind of story
Full story timeline · 4 updates
- Fri 30 OctoberMalicious Claude Code VS Code Extension Installs Persistent SSH Backdoor to Give Attackers Remote AccessGBHackers
- Official Claude Code VS Code Extension Compromised to Install Persistent SSH BackdoorThe Hacker News
- Sat 31 OctoberHackers Distribute Malicious Claude Code Extension on Cursor Marketplace to Install Persistent SSH BackdoorGBHackers
- Mon 2 NovemberMalicious Claude Code Extensions in Cursor Marketplace Install Persistent SSH Backdoors on Windows and macOSGBHackers
Who reported · 2 outlets
GBHackersThe Hacker News
Who and what is in it
Products