Anthropic got compromised.
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@GossiTheDog@cyberplace.social This whole thing makes me SO confused? What even is Open VSX and what actually uses that for extensions? I would assume VS Code only uses official marketplace?
Then I took a look at the Open VSX registry and the Claude Code for VS Code is just uploaded by some random entity called
igorkofman?EDIT: Does vscodium use Open VSX?
EDIT 2: Why does Open VSX have 63M downloads while official marketplace has 29M downloads???
EDIT 3: I read the article again
Open VSX serves extensions to VS Code-compatible editors like Cursor and Windsurf.
aaaaa lmao that also explains the amount of downloads being different. Fair to assume that literal AI editors has more downloads for Claude Code than just vscode/vscodium
@jalict @GossiTheDog Thanks I was also confused about this, very helpful!
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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 anthropic says they were not compromised, but that cursor has been: https://news.ycombinator.com/item?id=50304129
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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 Apparently no loser thinking there!

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So, stupid question: if it was not igorkofman's systems or accounts that were compromised but Open-VSX itself, then what are the chances that the only extension compromised today is the Claude Code one?
Ok, so it seems that Cursor has some overlay over Open-VSX. If Anthropic is working specifically with Cursor then the damage might actually be limited to Cursor? Gotta ask again, though, what are the odds that only the Claude Code extension was compromised? Assuming the payload of the hack is the same and the detection signals are, my guess is that anyone using Cursor should use the detection steps published just in case.
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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.
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@GossiTheDog If I was a snarky person, I would ask what the difference between normal Claude Code and malware is, but that would be mean to all my token spinning siblings.
@bremner @GossiTheDog the old joke about Windows installation CDs playing satanic music when read backwards and installing Windows when read forwards.
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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.
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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 seems like only the Cursor version was compromised: https://opensourcemalware.com/blog/trojanized-claude-code-extension-plants-persistent-ssh-backdoor
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@Frekason @GossiTheDog And actually, same question about Microsoft's marketplace. Phorion only seems to mention Cursor's Marketplace.
@tobiasgies @Frekason @GossiTheDog phorion is a corporation providing security related software and service specifically for itoddlers. odds are that they didn't even look at microslop's marketplace since it's not relevant to their itoddler market.
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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 Got compromised? Or working as designed?
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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 Shout out to all my homies running neither VSCode nor Claude!
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Anthropic's Claude Code Cursor extension was also compromised, same remote access backdoor https://cursor.com/blog/claude-code-extension-security-notice
Anthropic still haven't admitted what has happened.
@GossiTheDog
Any recommendations for non-developer/non-security expert end users wanting to check if their personal devices are compromised? -
@GossiTheDog If you let AI:s and agent roam around your production environment without oversight or security, you deserve everything that might happen to you.
The recent AI security scare is as if the world IT-workers have gotten mind wiped and are only now relearning basic rules of security that were known 20-30-40 years ago.
@h4890
> the world IT-workers have gotten mind wipedYes. All not wiped enough were fired, some smart ones still cling to the desks but are in hiding, pretending they also were ai-debrained.
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@jalict @GossiTheDog Thanks I was also confused about this, very helpful!
@prism@infosec.exchange @GossiTheDog@cyberplace.social Happy to hear!
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I've confirmed Binance use Claude Code on Cursor with this extension.
@GossiTheDog ROFLMAO
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@GossiTheDog with no comms from Anthropic, are there any concrete recommendations? I can think of at least one person I know who might be impacted by this.
@huronbikes @GossiTheDog Yes, of course there are recommendations. Uninstall Claude.
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@huronbikes @GossiTheDog I'd go with:
Disconnect from any network
Save your data (only) to removable storage
Erase and reinstall from media.Essentially, 'Nuke it from orbit'
I recognise this might be a bit draconian for many, though.@tjbutt58 @huronbikes @GossiTheDog What if it's in the UEFI firmware, eh?
https://firmguard.com/the-6-unparalleled-uefi-bios-firmware-attacks-and-their-impact/
When they say nuke the site from orbit they do mean nuke the entire thing from orbit, not reinstall some piece of software on a computer. You need to nuke the entire machine, it's the only way to be sure.
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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 "A malicious actor used access to Cursor’s marketplace to publish a tampered extension targeting Cursor's users, we were not involved with building, publishing, or hosting this. The versions on our official channels including VS Code and OpenVSX are not affected and this only impacts Cursor users." https://news.ycombinator.com/item?id=50305139
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Anthropic's Claude Code Cursor extension was also compromised, same remote access backdoor https://cursor.com/blog/claude-code-extension-security-notice
Anthropic still haven't admitted what has happened.
@GossiTheDog per these comments it was a forged version inside Cursor’s own extension marketplace, not a package published by/as Anthropic to the wider one https://news.ycombinator.com/item?id=50304129
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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 anthropic are now quite directly saying it is not their account and implying cursor's marketplace was compromised. it wasn't on OpenVSX, only Cursor's weirdo version
https://news.ycombinator.com/item?id=50304129