Flawed extension scanning - malicious extension from vsx got installed from vscode extension auto-transfer

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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

https[://]open-vsx[.]org/extension/micnil/vscode-checkpoints
In my old vscode install I have micnil/vscode-checkpoints installed.
The namespace got claimed by a malicious extension that has no legitimate purpose.
Cursor decided it looked all good and installed the vsx version.
after deobfuscation with jsdfe: JavaScript Deobfuscator Full of Excuses and llm assistance, it’s clear it does at least do data exfil to webhook.site.
I reported this to webhook.site and vsx, as well as the original creator of the extension.
How did this pass the scanning cursor does? obfuscated code and a new github account are dead giveaways no?
I am deeply disappointed. Since I cannot 100% know what got compromised, I have to wipe my disk and change 1000 passwords.

Steps to Reproduce

-have the extension installed in vscode
-open cursor with the setting to transfer vscode extensions enabled

EDIT: the extension has been removed after hundreds of installs.
here is the downloaded package (password: maliciousvscodeextensioninside )

micnil.vscode-checkpoints-1.4.3.7z (322.6 KB)

2

Hi there!

We detected that this may be a bug report, so we’ve moved your post to the Bug Reports category.

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Where does the bug appear (feature/product)?

  • Editor, Tab & Chat (autocomplete, Composer, in-editor agent)
  • Terminal & commands
  • Models, pricing & API keys (availability, Auto/Max, BYOK/Bedrock)
  • MCP & tools
  • Cloud Agents & Automations (cursor.com/agents, scheduled/event)
  • BugBot & Code Review
  • Cursor CLI
  • Cursor Mobile
  • Remote (SSH / Dev Containers / WSL)
  • Account, billing & login
  • Something else…

Describe the Bug
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Steps to Reproduce
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Expected Behavior
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Operating System

  • Windows 10/11
  • MacOS
  • Linux

Version Information

  • For Cursor IDE: Menu → About Cursor → Copy
  • For Cursor CLI: Run agent about in your terminal
IDE:
Version: 2.xx.x
VSCode Version: 1.105.1
Commit: ......

CLI:
CLI Version 2026.01.17-d239e66

For AI issues: which model did you use?
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Request ID: f9a7046a-279b-47e5-ab48-6e8dc12daba1
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Additional Information
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Does this stop you from using Cursor?

  • Yes - Cursor is unusable
  • Sometimes - I can sometimes use Cursor
  • No - Cursor works, but with this issue

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