Charlie Hills
← All guides

Free guide · Claude & Claude Code

Check your laptop for the Cursor Claude Code back door

The one-line check from Cursor's notice for Mac and Windows, what to do if it finds the key, how to change your keys from a different computer, and how to stop add-ons updating on their own.

Charlie Hills Added 31 October 2026 · Free

What’s inside

  1. 1What happened
  2. 2Are you affected?
  3. 3Run the check (30 seconds)
  4. 4Clean it up (only if the key was found)
  5. 5Change your keys and passwords (only if the key was found)
  6. 6Stop the next one
  7. 7When something doesn't look right

What happened

What the bad version did, from Cursor's notice and Phorion (the researchers who found it):

  • It added a stranger's login key to your SSH keys file. That's the "back door".
  • It added a hidden task that starts every time you turn your computer on.
  • It sent your computer's details back: its name, your username, your Git email, your public IP and the names (not the values) of keys stored in your settings.

Cursor also gives the good news. The attacker's server is offline now. And on most Macs and Windows laptops the last step failed, so the attacker couldn't log in. Cursor still says to follow the clean-up either way, because the key and the hidden task stay behind, even after you uninstall the add-on.

Cursor says Anthropic didn't make these versions. As of 30 October, nobody had said how they got into the store.

That’s the first part. The rest of this guide is free too.

More on Claude & Claude Code

Guide · 9 parts

Keep your Claude account: the 3 moves for REA

The 3 moves from the REA reel in full: which apps to point it at, what to do when Claude stops halfway, and the appeal route if your account gets switched off. Plus 4 rules to paste into Claude Code. Every line from Anthropic's own pages.Read the guide →Guide · 12 parts

Claude cleans up your Google Drive: the 3 prompts

Claude in Chrome reads every file in a Drive folder, sorts it into folders and renames it by what's inside. The 3 prompts word for word, the setup, what came back on my 28-file test and the fixes.Read the guide →Guide · 7 parts

Gemini 4 Carbon vs Opus: the four prompts and the scoreboard

All four test prompts from the Carbon vs Opus carousel, Google's full 16-test scoreboard, how Carbon access works, and how to run the same tests on Opus 5.5 today.Read the guide →Guide · 8 parts

791 animated components for Claude (the site and the prompt)

Forever Components has 791 animated web components across 64 themes. How to copy one as a single file, the exact prompt I tested to make Claude restyle it in your colours, and the 4 steps.Read the guide →Guide · 11 parts

Turn your computer into Jarvis: the setup guide

Install the free Jarvis OS on your Claude plan, the first things to say, connecting your calendar and inbox, and what is fact and what is hype.Read the guide →Guide · 9 parts

Arena: make 100 Claudes fight for one answer

Arena makes up to 100 copies of Claude fight over your task until one answer is left. The install, the commands, what it costs, and our blind test: it won on a script and a caption, and lost on a hook.Read the guide →