Poisoned Claude Code extension on Open VSX planted an SSH backdoor
Version 2.1.313 was on Cursor’s marketplace for about 11 hours; Cursor says at most 5,000 users were affected.
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Product
Open VSX
- Mentions · 7d2
- Mentions · 30d4
- All mentions5
- First seenSep 1, 2026
- Last mentioned16h ago
Timeline
5 articles · newest firstMalicious Claude Code extension on Open VSX plants an SSH backdoor
OpenSourceMalware says anthropic.claude-code 2.1.313 adds an SSH key, reverse tunnel, and startup scripts; Anthropic’s official release is not shown compromised.
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ThreatsDay: Ransomware Affiliate Betrayal, WhatsApp RAT, Exposed Hacker Tools and 12 More Stories
A ThreatsDay roundup covers GlassWorm VS Code themes, VulcanRAT207, a Qilin extradition, and a rogue Gentlemen affiliate.
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GlassWorm Supply Chain Attack Uses Fake VS Code Themes to Deliver Hidden Malware
GlassWorm-linked VS Code theme extensions hide downloaders that fetch Windows malware, including a blockchain-addressed in-memory loader.
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Open VSX Removes 77 Malicious Evil Twin Extensions Exfiltrating Developer Data
77 malicious 'evil twin' Open VSX extensions impersonated developer tools and exfiltrated hostnames and detailed workspace reconnaissance to mangorbit.com.
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Appears with
- Microsoftvendor · 3
- Visual Studio Codeproduct · 3
- Claude Codeproduct · 2
- Socketorganization · 2
- Anthropicvendor · 2
- GlassWormmalware · 2
- Microsoftorganization · 2
- BraZetsumalware · 1
- Qilinthreat actor · 1
- Shai-Huludmalware · 1
- Bunvendor · 1
- Phorionorganization · 1
- Gentlemenmalware · 1
- Socketvendor · 1
- Azazelthreat actor · 1
- Open VSXorganization · 1
Entities are extracted by the model from each article. First seen , last mentioned . Watching keeps it in this browser only (no account); the watchlist page and dashboard alerts use it.