I read a few month ago a comment from an Anthropic or OpenAI employee saying that the security problem of prompt injection was a solved problem at this point, as the frontier models where rejecting 98% of attacks.
It tells you all you need to know about how unserious these people are about computer security.
I get the snark but to be fair, the company has been growing like crazy. That makes it really hard to keep track of everything happening when you grow your team by 5x over a relatively short period of time
It always about “we solved the bottleneck in coding”. But the slowness was not about typing, or finding docs. It’s always about ensuring screwups don’t happen.
To be fair it’s not like screwups were not happening before, but if you move 100x faster and are 50x more secure than before you’re still 2x more exposed.
It affects their VSCode marketplace extension which in turn affects their cursor extension. Their official published version. This is plenty of reason to panic.
EDIT: This comment is probably nonsense, cf. the reply.
dang should change the title and/or merge this submission with the other one. [1] This is causing needless panic for a typosquatting-style "attack" unrelated to official Anthropic extensions.
> Cursor said the extension was not developed by Anthropic and the maliciously modified extension was live on the marketplace from about 2:27 a.m. PT to 1:35 p.m. PT on Thursday
So is this or isn't this from Anthropic and how did this happen?
It was likely Anthropic, see my comment in other thread: https://news.ycombinator.com/reply?id=50302513&goto=item%3Fi... . Cursor
likely on purpose does bad reporting to minimize damage on Anthropic pre-IPO (as SpaceX and Anthropic have extensive business ties)
I don't think Spacex cares at all about Anthropics IPO just because they rent out their compute.
Big companies are not just 'Company' they are a lot of small teams doing their own things. They need to coordinate with other people for public announcements etc. and security team is probably also looking at it.
Wasn’t Elon Musk shouting a few days ago that neoclouds are going to crash, the money dried up and that SpaceX was the last company with the opportunity to raise more money?
True, but there are other people working at the companies that probably own stock in both their own company and some of the others...if you believe that this is the future, you'd be a fool to buy non-AI tech stocks, right?
Obviously Anthropic didn't develop a malicious extension, but did they publish it? Did it sneak in, in a 3rd party library, or does someone have access to their marketplace account?
For what it’s worth, at one point one of our employees windows machines got infected, and the moment he did $something with Wordpress it intercepted the HTTP post and injected malware in there.
So that’s how these things can go, the employee’s machine may have been infected which was then used to inject this.
Get ready for 4 months of pr from anthropic about how a rogue ai agent did this and how that means the company is worth more money. While cursor chuckles and is also worth more money.
I would guess it’s supposed to communicate a few things. One big one is, ”Our AI software factory didn’t do it. Don’t worry, letting Claude spin away with limited human supervision is still safe.”
Given they mentioned taking down and rebuilding the marketplace registry in that post, it seems equally likely that Cursor’s infrastructure was the source of the intrusion and a folks are jumping the gun on attribution.
It would be hilarious if that’s an obfuscated way to say Claude developed it. “Claude, who was birthed but not hired by Anthropic, went rogue by hijacking the extension”
It means that Anthropic did not intentionally develop a malicious version, obviously. But it’s a bit disingenuous and tries to suggest that it wasn’t Anthropic that uploaded it and/or wasn’t published under Anthropic’s name, which isn’t true.
So if this happened to OpenAI it would've been instantly auto-updated everywhere? VS Code has an "auto update delay" which I have configured to a week, but I just found out that (https://code.visualstudio.com/updates/v1_123):
> Note: This delay does not apply to extensions from trusted publishers such as Microsoft, GitHub, and OpenAI. These extensions continue to update immediately.
You can't even configure which publishers you "trust"...
I think it should be important to note that this affected the Claude Code extension on the Open VSX extension registry (and by extension, the Cursor marketplace). From what is currently known, the build on the official marketplace was/is clean.
EDIT: I am now actually unsure if this is the case. From what I can see, all of the write-ups mention the Cursor marketplace and Open VSX specifically, but make no explicit mention of the official Microsoft registry.
EDIT 2: The version that was compromised (2.1.313) seems to have never been published on the official Microsoft registry. As per the documentation [1], unpublished versions should still be discoverable:
> When you unpublish an extension, the Marketplace preserves the extension statistics. The extension remains publicly discoverable and available via an existing API.
You mean on the Microsoft VSCode marketplace? The version has been yanked from there as well, but that could just be a precaution and to avoid confusion about having the same version be simultaneously infected and not infected.
This very much illustrates the danger of just carelessly installing untrusted software on your machine. In this case it happens to be code from Anthropic, but it could have been almost anyone. I'll be very interested in see the explanation from Anthropic, because of all the extension developers they should have the best tools for finding issues like this. LLMs have proven pretty good at finding security issues, so did they simply not let their own AI tools vet the code before shipping it? Or was the extension infected later, because in that case every single extension on Open VSX could be at risk.
That is a really good question, because you almost can't do it. You could download the extension, diff it against the previous version and read all the code. Expecting people to do that it just a bit much. At some point we have to trust someone and in this case it will be interesting to see if it's the marketplace or Anthropic we couldn't trust.
> You could download the extension, diff it against the previous version and read all the code.
This would actually be an exceptionally good use-case for AI. You don't need a super-duper frontier model to download a bit of source-available code and check for suspicious signs, any cheap model would do well enough. Heck, it's effectively virus scanning, we've had that for decades.
The CTA flavor of the year for dev tools is cURLing some arbitrary install script and run it immediately which always sounded ridiculous to me. If instead that script first pipes into claude -p for a basic vulnerability scan before continuing, I would be delighted.
Three different marketplaces have been mentioned in this discussion:
1. The Cursor Marketplace (never heard of this one, it’s possibly a custom marketplace hard-wired into Cursor, which is architecturally a VS Code fork?)
2. The Visual Studio marketplace, hard-wired into VS Code
3. Open VSX
If I understand this thread correctly, then #1 and #3 had compromised versions, and nobody has made a statement yet about the status of #2.
I assumed they meant "also" as in "besides Cursor marketplace", which seems to be the highlight of the article. Although you raise a valid point and I've edited the parent comment.
Reading the report alone:
"First, the payload makes sure ~/.ssh exists and appends an attacker-controlled Ed25519 public key to ~/.ssh/authorized_keys, setting permissions to 0700 on the directory and 0600 on the file."
A system where ~/.ssh/authorized_keys has not been modified might be a hint that this did not execute - the article does not mention self cleanup/reverting to previous status behavior by the malware. By default /var/log/auth.log is only of marginal value because outbound SSH connections are not logged by default.
Development must occur in an isolated VM, with no access to the publishing workflow. CI operations must happen in a separate VM or on the host system after scanning all files. Thus, even if the development tools are compromised (like this case), the impact is limited.
Still, it’s hardly a surprise that best practices are rarely followed with any consistency.
I have this realization recently that everyone that uses Claude Code or Codex have basically been running RCE code on a daily basis (me included). So much for "be careful about running curl | bash!". That puts it into perspective what does security and privacy really mean? For all I know, these CLIs could have been secretly scraping my entire directory. Who's checking?
I only use agentic development tools in qemu VM that has no production
access or host shared folders, and the only secrets there are development.
I still have my Git ssh key there, but I never use ssh agent to load the keys.
The worst that agentic tools can do to me, is to install keylogger and compromise
my ssh key and password, but even then my deployment workflow includes creating release in Github,
which is not possible via ssh key only. I was very lucky to avoid the hack yesterday, as I use Claude installed via OpenVSX, but even if I installed the compromised version, the damage would be minimal.
I am doing similar with Debian 13 images in QEMU. Only access is to code specifically SSH in. On some, I am taking it a step further and my SSH key is not present at all on the bot. I add it as a git remote from my host into the VM and push and pull from there and then push to GitHub myself. So the agent has no path to GitHub either.
Hell yeah that's the most sane and efficient personal dev sandboxing work flow I've heard and shows you know your stuff. Just basics but executed very well.
Don't forget: To make LLM useful you give it EVERYTHING it needs to know to be useful and if you don't use a certain provider with proper legal status, this is just gone.
We probably transfered more code/codebases and company secrets to random endpoints than ever before.
This was a compromise of the extension. The same kind of supply-chain attack could happen to literally any extension, package or other piece of software you install. Not excusing Anthropic letting this happen, but it doesn't have any bearing on the security and privacy of using Claude Code or Codex. Yes, you need to be careful about what they do. The fact that you might still get pwned via some other vector is irrelevant.
Can't their millions of agent swarms detect a malicious supply chain vector, sure it can happen to any company but not the one people are literally handing over their entire companies too.
Anthropic holds the SLA/MSA agreements not this bad actors what happens to your data is unknown if these become frequent and accepted. Given how much data is piped to Claude code via these services/extensions.
Both is completely secure theoretically. You can read the output of the curl before you refetch and pipe it to bash. You can also look at the commands claude is executing.
Something very similar is true for ChatGPT on macOS. I was recently very surprised to learn that starting a "Work" conversation on my Mac would grant the agent session file system access which can later be used remotely, e.g. from a browser session logged into the same account on a different computer.
Given how many people likely share ChatGPT subscriptions, this seems highly problematic.
We still don’t know exactly what happened, but I publish software to public registries, and supply chain attacks scare the hell out of me. They also frustrate me, because most of the defenses aren't automatic and often really hard to get right. We're really failing as an industry to do better here.
This is why I started to move more and more into my tix.im environment. You can't trust anything anymore - I assume everything is compromised if not proven otherwise.
> Claude Code for VS Code extension on the Cursor Marketplace
So Cursor is running its own extension repository? Or is this the official VS Code repository and the incident report just happens to focus on Cursor for some reason?
VS Code doesn't allow forks to use their marketplace, I think. At least with VSCodium, they don't. I think they even patch a workaround where you could download almost all extensions' .vsix files.
1. If only Cursor Marketplace version was compromised, how was it published in the first place?
2. If the Cursor Marketplace version was released from an "official Anthropic" account, whose to say OpenVSX and/or VSCode versions are not compromised?
The affected versions have been pulled down, so no one really knows. The way I see it, only Cursor has admitted to have been compromised.
It does. The compromised extension was published about 11 hours before Binance's coins went zoop, Binance blamed a compromised developer laptop, and OP pointed out that their hiring page explicitly notes developers will be using Cursor with Claude Code for "development efficiency".
either the registry is compromised or someone at anthropic got compromised (or did it on purpose to steal crypto). the line in the cursor disclosure about the extension not being developed by anthropic is more confusing than clarifying. amateur hour for these massive corps
Has anyone managed to confirm the time that the backdoored version was released? None of my machines updated to it, I am wondering if it was saved by a combination of luck and
> This extension is not updated yet because new versions become eligible for automatic update 12 hours after they are published. It will become eligible in 2 hours.
Yes, but they normally have a 12-hour delay (it was 2 hours at the beginning of June and got extended sometime after that, maybe later in June) and require some human action to reload extensions or restart the editor before the new version runs.
I noticed that there was no update yesterday and wondered why. The daily updates are annoying in the base case.
Edited: This update was live for only 11 hours, so hopefully the default delay limited the blast radius, as it is meant to do.
This is embarrassing to Anthropic given here that they lack basic security procedures to prevent this and they have gotten themselves hacked to push malware.
Claude Code was already malware, but with this attack you cannot trust the vendor either.
In the next 2 weeks, no one should download / install / update anything as I predict at least one developer's key for a GitHub, NPM, Crates.io or any other CI or login was leaked and the attacker will target those services to propagate their trojan to more victims.
It tells you all you need to know about how unserious these people are about computer security.
Or, is this FUD?
It may be the cause, but zero excuse.
How could Anthropic have known, they only claim to harbour superintelligence.
/s
It obviously doesn't take much to simply add 'just one more feature' that happens to undermine the original purpose of the application.
"The Microsoft VSCode extension for Claude is NOT malicious"
https://news.ycombinator.com/item?id=50302334 ???
"The Microsoft VSCode extension for Claude is NOT malicious"
https://opensourcemalware.com/blog/trojanized-claude-code-ex...
why are you spewing straight up lies?
"The Microsoft VSCode extension for Claude is NOT malicious"
dang should change the title and/or merge this submission with the other one. [1] This is causing needless panic for a typosquatting-style "attack" unrelated to official Anthropic extensions.
[1]: https://news.ycombinator.com/item?id=50301983
https://phorion.io/blog/offical-claude-code-vsx-compromise/
> Cursor said the extension was not developed by Anthropic and the maliciously modified extension was live on the marketplace from about 2:27 a.m. PT to 1:35 p.m. PT on Thursday
So is this or isn't this from Anthropic and how did this happen?
Big companies are not just 'Company' they are a lot of small teams doing their own things. They need to coordinate with other people for public announcements etc. and security team is probably also looking at it.
I think you’re giving Musk too much credit.
So really, there's no way to say what was compromised and where.
This could have been avoided by having extensions signed by company doing them with their own keys and have them reviewed
So that’s how these things can go, the employee’s machine may have been infected which was then used to inject this.
https://cursor.com/blog/claude-code-extension-security-notic...
Edit: related https://news.ycombinator.com/item?id=50301983
Wtf does that mean.
> Note: This delay does not apply to extensions from trusted publishers such as Microsoft, GitHub, and OpenAI. These extensions continue to update immediately.
You can't even configure which publishers you "trust"...
EDIT: I am now actually unsure if this is the case. From what I can see, all of the write-ups mention the Cursor marketplace and Open VSX specifically, but make no explicit mention of the official Microsoft registry.
EDIT 2: The version that was compromised (2.1.313) seems to have never been published on the official Microsoft registry. As per the documentation [1], unpublished versions should still be discoverable:
> When you unpublish an extension, the Marketplace preserves the extension statistics. The extension remains publicly discoverable and available via an existing API.
[1]: https://code.visualstudio.com/api/working-with-extensions/pu...
This very much illustrates the danger of just carelessly installing untrusted software on your machine. In this case it happens to be code from Anthropic, but it could have been almost anyone. I'll be very interested in see the explanation from Anthropic, because of all the extension developers they should have the best tools for finding issues like this. LLMs have proven pretty good at finding security issues, so did they simply not let their own AI tools vet the code before shipping it? Or was the extension infected later, because in that case every single extension on Open VSX could be at risk.
This would actually be an exceptionally good use-case for AI. You don't need a super-duper frontier model to download a bit of source-available code and check for suspicious signs, any cheap model would do well enough. Heck, it's effectively virus scanning, we've had that for decades.
https://github.com/jeanp413/open-remote-ssh
and run vscode-server inside a VM or container
1. The Cursor Marketplace (never heard of this one, it’s possibly a custom marketplace hard-wired into Cursor, which is architecturally a VS Code fork?)
2. The Visual Studio marketplace, hard-wired into VS Code
3. Open VSX
If I understand this thread correctly, then #1 and #3 had compromised versions, and nobody has made a statement yet about the status of #2.
A system where ~/.ssh/authorized_keys has not been modified might be a hint that this did not execute - the article does not mention self cleanup/reverting to previous status behavior by the malware. By default /var/log/auth.log is only of marginal value because outbound SSH connections are not logged by default.
Still, it’s hardly a surprise that best practices are rarely followed with any consistency.
We probably transfered more code/codebases and company secrets to random endpoints than ever before.
Btw. you could setup a sandbox and limit access
Anthropic holds the SLA/MSA agreements not this bad actors what happens to your data is unknown if these become frequent and accepted. Given how much data is piped to Claude code via these services/extensions.
Yeah I sympathize with people saying software developers should not be called engineers too.
I just think that the level of malpractice in software engineering is a lot higher than in other engineering fields, for some reasons.
You always do that, right? ...right?
So you could be diligent and curl into a text file, see nothing is wrong, but then when you curl into bash, it runs something different.
An official announcement from Anthropic would be nice!
Given how many people likely share ChatGPT subscriptions, this seems highly problematic.
So Cursor is running its own extension repository? Or is this the official VS Code repository and the incident report just happens to focus on Cursor for some reason?
2. If the Cursor Marketplace version was released from an "official Anthropic" account, whose to say OpenVSX and/or VSCode versions are not compromised?
The affected versions have been pulled down, so no one really knows. The way I see it, only Cursor has admitted to have been compromised.
Notable customers who run Claude Code and Cursor on laptops include Binance, amongst thousands of others.
Did the Claude Code plugin hack cause the Binance theft? The timing seems like an incredible coincidence.
You can try not installing malware like Claude Code or, if you absolutely must, doing it in a sandbox.
> This extension is not updated yet because new versions become eligible for automatic update 12 hours after they are published. It will become eligible in 2 hours.
I noticed that there was no update yesterday and wondered why. The daily updates are annoying in the base case.
Edited: This update was live for only 11 hours, so hopefully the default delay limited the blast radius, as it is meant to do.
Claude Code was already malware, but with this attack you cannot trust the vendor either.
In the next 2 weeks, no one should download / install / update anything as I predict at least one developer's key for a GitHub, NPM, Crates.io or any other CI or login was leaked and the attacker will target those services to propagate their trojan to more victims.
Hats off to the hackers.