Anthropic got compromised.
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@GossiTheDog
Let me get this straight:
The Cursor (which uses Open VSX Registry)anthropic.claude-codeextension was backdoored, but the VS Codeanthropic.claude-codeextension was not? The former maintained by "Igor Kofman", and the latter by "Anthropic". Igor Kofman being an Anthropic employee and all. 2.1.314, which removes the backdoor was released to both marketplaces. Also, the original Phorion blog post has removed every mention of VSX except for in the URI.There a bit of hand-waving and lacking information to prevent the masses from knowing exactly what happened, and how, and who all is affected.
@wdormann @GossiTheDog I wonder about Windsurf, which uses the VSCode marketplace.
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@GossiTheDog
Let me get this straight:
The Cursor (which uses Open VSX Registry)anthropic.claude-codeextension was backdoored, but the VS Codeanthropic.claude-codeextension was not? The former maintained by "Igor Kofman", and the latter by "Anthropic". Igor Kofman being an Anthropic employee and all. 2.1.314, which removes the backdoor was released to both marketplaces. Also, the original Phorion blog post has removed every mention of VSX except for in the URI.There a bit of hand-waving and lacking information to prevent the masses from knowing exactly what happened, and how, and who all is affected.
@wdormann it took several hours to shake out the details but that looks to be the shape of it.
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@wdormann @GossiTheDog I wonder about Windsurf, which uses the VSCode marketplace.
@huronbikes @GossiTheDog
I'm pretty sure that Windsurf uses the same Open VSX Registry that Cursor does. -
I'm confirmed the new, replacement versions Anthropic published overnight (which auto update) do *not* remove the prior backdoors and recon activity. So SSH still reverse calls out etc, you need to manually remediate every impacted VSCode and Cursor system.
Anthropic *must* tell customers what happened in a completely transparent way.
@GossiTheDog Who needs Anthropic?
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@wdormann it took several hours to shake out the details but that looks to be the shape of it.
@GossiTheDog
Aren't there other consumers of the Open VSX Registry? In which case this incident is not limited to Cursor? -
I've written a blog - Anthropic have been hacked to deliver remote access malware to millions of endpoints where developers use Claude Code.
@GossiTheDog I hope that all the financial analysts who are responsible for due diligence on the upcoming Anthropic public offering see both the report and Anthropic’s lack of response. The legal bills and reputation loss could be staggering.
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@GossiTheDog
Aren't there other consumers of the Open VSX Registry? In which case this incident is not limited to Cursor?@wdormann so that bit is unclear. They have some kind of proxy to it apparently. At the minute Anthropic refuse to say anything - they no commented my blog too, and Cursor is busy trying to downplay that anything happened.
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I've written a blog - Anthropic have been hacked to deliver remote access malware to millions of endpoints where developers use Claude Code.
@GossiTheDog
in your medium post are some extraneous words:
“the malicious version was silently deleted the backdoored version” -
Anthropic got compromised.
Their Claude Code extension on Visual Studio has malware in it, which creates a remote access Trojan to desktops.
@GossiTheDog LOL
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@GossiTheDog odds on this being a factor in how binance got done over?
Very likely, I'd say.
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@wdormann so that bit is unclear. They have some kind of proxy to it apparently. At the minute Anthropic refuse to say anything - they no commented my blog too, and Cursor is busy trying to downplay that anything happened.
@GossiTheDog
Neat.If we look at the claude code tags in github (including searching git logs) or the Open VSX Registry, I see no mention of
2.1.313anywhere.There is one single github user that mentions 2.1.313 release notes in a sort of canned footer in 6 tickets that were all created 10 hours ago, though.
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@datarama @GossiTheDog
"The agents went wild and wanted to expand to more computers" - definitely not "We vibe code our security"@cdamian @datarama @GossiTheDog
"The Basilisk wanted more funding. We have been informed that all those affected will be viewed with slightly less malice by the Basilisk, once its time comes"
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@GossiTheDog
Neat.If we look at the claude code tags in github (including searching git logs) or the Open VSX Registry, I see no mention of
2.1.313anywhere.There is one single github user that mentions 2.1.313 release notes in a sort of canned footer in 6 tickets that were all created 10 hours ago, though.
@wdormann @GossiTheDog everyone has ceded software engineering to a firm which clearly knows nothing about software security and this is why we can’t have nice things
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Anthropic got compromised.
Their Claude Code extension on Visual Studio has malware in it, which creates a remote access Trojan to desktops.
@GossiTheDog
Er moet nog veel meer gehackt worden bij Claude tot in de core. -
@wdormann so that bit is unclear. They have some kind of proxy to it apparently. At the minute Anthropic refuse to say anything - they no commented my blog too, and Cursor is busy trying to downplay that anything happened.
@GossiTheDog @wdormann the phorion blogpost has been updated to remove any screenshot and mention of Open VSX.
it would have been great if they mentionned the edit and the reason behind it... -
@GossiTheDog @wdormann the phorion blogpost has been updated to remove any screenshot and mention of Open VSX.
it would have been great if they mentionned the edit and the reason behind it...@kolo @GossiTheDog
Except for in the URIhttps://phorion.io/blog/offical-claude-code-vsx-compromise/ -
Cursor statement "This malicious version of the extension was not developed by Anthropic" is a bit wordsmithy. "Developed" is doing some heavy lifting - it was uploaded to Anthropic's verified account and Cursor automatically updates extensions.
Cursor say around 5k developer systems were impacted.
@GossiTheDog jeeze did you sleep at all last night?
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@GossiTheDog Who's gonna put their money on this being an inside job?
That's right, my theory is that they vibe coded the extension, and Claude regurgitated some compromised code into it.
Keep in mind that it's training data most certainly contains many instances of backdoors from some obscure corners of many Github/Gitlab repositories from over a wide timespan.@alice_pea_3526 @GossiTheDog What a wild week it's been for cybercrime.
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Anthropic got compromised.
Their Claude Code extension on Visual Studio has malware in it, which creates a remote access Trojan to desktops.
@GossiTheDog I do wonder that things like this had not happened before - or they did, but we didn't learn about it?
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To be clear this is a supply chain attack, the threat actor got reverse SSH (command line) connectivity to Anthropic customer environments at scale.
@GossiTheDog allowing outbound ssh is the most dangerous firewall rule
