Malicious Claude Code extension on Cursor marketplace planted SSH backdoors for 11 hours
A fake "official" Claude Code update distributed through Cursor's marketplace on 29 October carried SSH backdoors for about 11 hours, prompting calls for deterministic outbound gates for AI agents.
Read the full story at Microsoft Research Blog ↗
Timeline · 30 reports
- 2026-11-01 14:22 · DEV Community — AI
Using Claude Code, Codex and Gemini CLI on the same repository - 2026-11-01 13:48 · DEV Community — AI
Malicious Claude Code Extensions in the Wild: Why AI Agents Need Deterministic Outbound Gates - 2026-11-01 12:10 · DEV Community — AI
Claude Code vs Codex: How I Use Both on One Repo - 2026-11-01 10:54 · DEV Community — AI
I gave Claude Code a crew. Codex and Gemini found a race in the plugin that runs them. - 2026-10-31 23:43 · DEV Community — AI
"Buddy: let Claude Code, Codex and other AI agents use your Android phone - 2026-10-31 21:00 · DEV Community — AI
I Let Claude Code Write a 20-Lesson Tutorial Course for My App From Its Codebase - 2026-10-31 18:30 · DEV Community — AI
A fake "official" Claude Code update planted SSH backdoors through Cursor's marketplace - 2026-10-31 14:01 · DEV Community — AI
Your AI coding transcripts are a secret store: where Claude Code, Codex, Cursor, Copilot and Antigravity keep them - 2026-10-31 13:20 · DEV Community — AI
Claude Code Extension Backdoor in Cursor: Uninstalling Won't Remove the SSH Key - 2026-10-31 11:30 · DEV Community — AI
How to Tell What Claude Code and Codex Forget When They Compact a Session - 2026-10-31 11:27 · The Next Web
Anthropic denies breach as tampered Claude Code extension hits Cursor users - 2026-10-31 09:38 · DEV Community — AI
A trojanized Claude Code extension reached the Cursor Marketplace too — here's a 7-point audit for your machine - 2026-10-31 08:15 · DEV Community — AI
Claude Code for VS Code 2.1.313 backdoor: how to check your machine and clean up - 2026-10-31 08:02 · DEV Community — AI
Two Claude Code sessions, one folder, no merge conflicts: how I split a hackathon build between AI agents - 2026-10-31 07:49 · DEV Community — AI
I'm 15, and I built an interactive vision simulator using Claude code, vanilla JS and CSS filters - 2026-10-31 05:00 · Techmeme
Anthropic says a malicious actor used access to Cursor's marketplace to publish a "tampered" copy of the Claude Code extension, which it didn't build or publish - 2026-10-31 01:02 · Microsoft Research Blog
Inside a malicious Claude Code-branded extension and its persistent SSH backdoor - 2026-10-30 21:09 · Ars Technica AI
Anthropic VS code extension on Cursor backdoored for nearly 12 hours - 2026-10-30 18:16 · The Decoder
Malicious Claude Code extension in Cursor's marketplace attempted remote access and data theft - 2026-10-30 17:29 · Fast Company AI
Hackers hijacked a Claude Code extension, exposing yet another new AI security risk - 2026-10-30 16:27 · The Register AI/ML
Anthropic: That Claude Code extension compromise… couldn't be us - 2026-10-30 14:36 · BleepingComputer
Malicious Claude Code extension on Cursor planted SSH backdoors - 2026-10-30 12:59 · r/ClaudeAI
A backdoored Claude Code extension hit up to 5,000 Cursor users - 2026-10-30 11:18 · r/LocalLLaMA
Official Claude Code VS Code Extension Compromised to Install Persistent SSH Backdoor - 2026-10-30 11:00 · Towards Data Science
Claude Code Mods: Custom Hooks to Fix My Biggest AI Coding Frustrations - 2026-10-30 08:55 · The Hacker News (security)
Official Claude Code Extension on Cursor Marketplace Trojanized with Persistent SSH Backdoor - 2026-10-30 08:33 · Reuters AI
Cursor says up to 5,000 users affected by tampered Claude Code extension - 2026-10-30 08:05 · Unite.AI
Cursor Discloses SSH Backdoor Attempt in Malicious Claude Code Extension - 2026-10-30 07:46 · AlphaSignal
Cursor's Claude Code Extension Was Hijacked, Exposing 5,000 Developers to SSH Backdoor - 2026-10-30 07:09 · Hacker News Front Page
Backdoor in Claude Code for VS Code extension on the Cursor Marketplace