# Trojanized Claude Code extension on Open VSX planted a persistent SSH backdoor

> Source: <https://runtimewire.com/article/trojanized-claude-code-extension-open-vsx-ssh-backdoor>
> Published: 2026-10-30 05:04:05+00:00

# Trojanized Claude Code extension on Open VSX planted a persistent SSH backdoor

**OpenSourceMalware analyzed version 2.1.313 on Open VSX and says its prepended loader added an SSH key, opened a reverse tunnel and set persistence.**

        By [Ryan Merket](https://runtimewire.com/author/ryan-merket)
        · Published 

Primary source: [x.com](https://x.com/adnanthekhan/status/2116010483702706337)

## Why it matters

Developer extensions run inside trusted IDEs with access to code, terminals and credentials. A trojanized artifact using the Claude Code package identity shows how registry distribution can turn that trust into persistent SSH access, even though the report does not prove Anthropic's official Marketplace release was compromised.

Security researcher [Adnan Khan (@adnanthekhan)](https://x.com/adnanthekhan) said on October 30th that a Claude Code VS Code extension had been backdoored, linking to an [OpenSourceMalware analysis](https://opensourcemalware.com/blog/trojanized-claude-code-extension-plants-persistent-ssh-backdoor) of a malicious artifact identified as 'anthropic.claude-code' version 2.1.313.…

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