> Yesterday, Anthropic were compromised and Cursor extension used by tens of millions of developers for Claude access was delivering a remote access trojan via an SSH reverse backdoor
That's a bit hyperbolic: someone released a version of the Claude Code VS Code extension with a backdoor on the Cursor marketplace:
> a maliciously modified version of Anthropic’s Claude Code extension was made available in the Cursor VS Code extension Marketplace
Cursor uses OpenVSX marketplace (https://open-vsx.org/), that all non-Microsoft forks of VSCode utilize
(official marketplace is only allowed in official proprietary VSCode release). It's not really related to Cursor/SpaceX in any way.
I suspect it's still Anthropic who were hacked, because they control OpenVSX
account with release privileges.
The affected Open VSX extension is owned by Anthropic employee Igor Kofman, but it is unclear whether his account or another part of the publishing process was compromised.
Sort of hoping it's Anthropic and their specific OpenVSX account credentials. As opposed to the worse case of an OpenVSX flaw that's broader. A ton of AI-enabled IDEs are VsCodium forks pointed at OpenVSX...Cursor, Anti Gravity, Kiro, Trae, Devin, etc.
Version 2.1.313 is missing from the official Claude Code GitHub repo's CHANGELOG[0]. There's also no tag[1] for 2.1.313[1], but 2.1.312[2], and 2.1.314[3] exist.
A malicious version of Anthropic’s Claude Code VS Code extension, version 2.1.313, was published to the Open VSX registry on Oct. 30. According to ChainCatcher, security researcher Paul McCarty, known as 6mile, described the finding in a post on the OpenSource Malware blog. Researchers confirmed the analyzed Open VSX release was malicious and submitted a threat report about the same version on Microsoft’s VS Code Marketplace as a precaution.
> Today we identified a security incident involving a specific extension package in the Cursor VS Code extension Marketplace: Anthropic.claude-code version 2.1.313. This malicious version of the extension was not developed by Anthropic. At most 5,000 users were affected, and we will reach out directly.
I mean, the title seems misleading at best. 3rd party extension, the kind you should not trust unless signed by somebody you trust.
If the sole purpose of this hack was to steal cryptocurrency, a silver lining might be, as in many similar cases, that if you stay away from that particular dumpster fire you are probably okay. I mean there's still a reverse shell on your machine to fix, but at least nothing of value was lost.
That's a bit hyperbolic: someone released a version of the Claude Code VS Code extension with a backdoor on the Cursor marketplace:
> a maliciously modified version of Anthropic’s Claude Code extension was made available in the Cursor VS Code extension Marketplace
https://cursor.com/blog/claude-code-extension-security-notic...
What appears to be an official Binance account reporting it also:
https://www.binance.com/en/square/post/10-30-2026-claude-cod...
I suspect it's still Anthropic who were hacked, because they control OpenVSX account with release privileges.
edit:
Binance confirms my suspicions, via https://www.binance.com/en/square/post/10-30-2026-claude-cod...
Version 2.1.313 is missing from the official Claude Code GitHub repo's CHANGELOG[0]. There's also no tag[1] for 2.1.313[1], but 2.1.312[2], and 2.1.314[3] exist.
0: https://github.com/anthropics/claude-code/blob/main/CHANGELO...
1: https://github.com/anthropics/claude-code/releases/tag/v2.1....
2: https://github.com/anthropics/claude-code/releases/tag/v2.1....
3: https://github.com/anthropics/claude-code/releases/tag/v2.1....
I don't use Cursor or the VSCode extension, but know plenty in our organisation who use the latter. How worried should we be?
A malicious version of Anthropic’s Claude Code VS Code extension, version 2.1.313, was published to the Open VSX registry on Oct. 30. According to ChainCatcher, security researcher Paul McCarty, known as 6mile, described the finding in a post on the OpenSource Malware blog. Researchers confirmed the analyzed Open VSX release was malicious and submitted a threat report about the same version on Microsoft’s VS Code Marketplace as a precaution.
I mean, the title seems misleading at best. 3rd party extension, the kind you should not trust unless signed by somebody you trust.
/s