Backdoors in official Claude Code extensions

(cyberplace.social)

292 points | by dsr_ 1 hour ago

19 comments

  • eviks 56 minutes ago
    That's literally impossible, with all the access to the frontier software development tools at their disposal they can ship features securely at 100x
    • stymaar 12 minutes ago
      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.

      • malfist 10 minutes ago
        I'm glad no one can steal from my bank, they stop 98% of thieves
      • palata 5 minutes ago
        [dead]
    • atrokhymchuk 25 minutes ago
      I am afraid until 200x is achieved we are at risk...
      • btown 17 minutes ago
        Only with two fully maxed subscriptions can we achieve this, and this is forbiddeneded
    • samiv 14 minutes ago
      Just put gastown on it!
    • kamban 49 minutes ago
      Yet, they managed to screw up.
      • iugtmkbdfil834 39 minutes ago
        :D I have to assume parent is being a little sarcastic.

        It obviously doesn't take much to simply add 'just one more feature' that happens to undermine the original purpose of the application.

        • skydhash 31 minutes ago
          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.
    • NewsaHackO 31 minutes ago
      Don't worry, it isn't, just a regular Anti-AI clickbait post. A fake Claude Code extension was available on Cursor (not VSCode regular). Uploaded by someone that wasn't Anthropic. 5k Cursor users affected.
  • AdrianCX 38 minutes ago
    https://www.reuters.com/business/media-telecom/cursor-says-u...

    > 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?

    • darkwi11ow 30 minutes ago
      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)
      • AdrianCX 18 minutes ago
        OpenVSX has no extension signing, no verification, nothing...

        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

      • origini 26 minutes ago
        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.

        • stopsayingsorry 20 minutes ago
          People at the top know that, once the music stops, the ball is over for everyone.
    • mrweasel 27 minutes ago
      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?
    • iugtmkbdfil834 37 minutes ago
      Isn't it fun when all the lines are blurred and it is hard to tell what belongs where?
  • altbdoor 1 hour ago
    • yubblegum 21 minutes ago
      > Cursor: "This malicious version of the extension was not developed by Anthropic."

      Wtf does that mean.

      • olmo23 12 minutes ago
        It sounds to me like they're saying it wasn't an Anthropic employee which decided to drop an SSH backdoor.
      • noitpmeder 18 minutes ago
        Just by people they paid to represent them.
      • sourcecodeplz 19 minutes ago
        someone got access to the account that can publish extension on cursor marketplace?
    • sharpshadow 27 minutes ago
      Looks like a solid response with instructions and scripts how to get rid of the infection, but it doesn’t explain how it got there.
  • anon-3988 40 minutes ago
    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?
    • origini 25 minutes ago
      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.

      Btw. you could setup a sandbox and limit access

    • staminade 35 minutes ago
      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.
      • minraws 18 minutes ago
        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.

    • raxxorraxor 9 minutes ago
      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.

      You always do that, right? ...right?

      • deadbabe 3 minutes ago
        No but we use MCP so we’re fine.
    • magnio 6 minutes ago
      > Who's checking?

      Yeah I sympathize with people saying software developers should not be called engineers too.

      • palata 1 minute ago
        I think that software engineering is very much engineering.

        I just think that the level of malpractice in software engineering is a lot higher than in other engineering fields, for some reasons.

    • snaking0776 33 minutes ago
    • Den_VR 34 minutes ago
      There’s a reason codex and the like improved like they did. You can simply look. Or hear about it on podcasts.
  • xx_ns 1 hour ago
    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.

    • mrweasel 1 hour ago
      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.

      • eviks 54 minutes ago
        What would be the careful way of installing the official extension?
        • mrweasel 35 minutes ago
          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.
          • toyg 9 minutes ago
            > 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.

        • READ_A_BOOK 47 minutes ago
          [dead]
    • misnome 53 minutes ago
      The screenshot is of the official marketplace
    • thevinter 1 hour ago
      Do you have any sources? OP claims that it *also* affects Open VSX
      • tveita 1 minute ago
        But the report OP cites at https://phorion.io/blog/offical-claude-code-vsx-compromise/ doesn't make a claim about Visual Studio Marketplace, only "the official Claude Code for VS Code extension bundle on the Cursor Marketplace"
      • Hackbraten 4 minutes ago
        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.

      • xx_ns 4 minutes ago
        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.
  • orlp 18 minutes ago
    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"...

  • stbenjam 31 minutes ago
    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.
    • poelzi 25 minutes ago
      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.
  • efficax 9 minutes ago
    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
  • HexDecOctBin 32 minutes ago
    > 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?

    • altbdoor 19 minutes ago
      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.

    • NewsaHackO 29 minutes ago
      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.
  • misnome 48 minutes ago
    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.

  • numbsafari 16 minutes ago
    This puts an entirely new spin on Elon trolling Binance on Twitter.
  • nubinetwork 1 hour ago
    It looks like they push an update every office day. I'm guessing if I installed 6 months ago and didn't update, that I should be fine?
    • staminade 41 minutes ago
      I think VS Code extensions autoupdate by default, unless you disable it.
      • entrope 30 minutes ago
        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.

    • fn-mote 1 hour ago
      Emphasis on guessing. If/when there is an actual postmortem, you’ll know when the back door was introduced.
    • fg137 58 minutes ago
      You are either lucky or compromised.
    • koolba 53 minutes ago
      Not updating air gapped systems is a security feature, not a bug.
  • poelzi 27 minutes ago
    I guess, this is why I'm building tix.im ...
  • hem777 1 hour ago
    ”I've confirmed Binance use Claude Code with this extension.”
    • fn-mote 1 hour ago
      ^^ Had to verify that this was a real quote from the chain and not a joke. It is accurate.
  • stopsayingsorry 56 minutes ago
    Imagine backdooring 50+ million installs.

    Hats off to the hackers.

    • stbenjam 52 minutes ago
      5,000*
      • gcoakes 30 minutes ago
        I think that's just the number Cursor has telemetry on. I think there's multiple distribution locations.
      • misnome 28 minutes ago
        5000 is the cursor number for people on the cursor version of the store, not the VSCode store.
  • primce1 29 minutes ago
    [flagged]
  • READ_A_BOOK 49 minutes ago
    [dead]
  • sick_of_slop 53 minutes ago
    [dead]