Zod 4.6.6 compromised by malware?
github.com
github.com
On September 21, someone used Colin's git credentials to push this compromised code into the project, Colin caught it, and reverted it that same day (PR #6620). He subsequently did release 4.6.6 on October 11, but it did NOT contain the infected code.
Btw, Zod wasn't the only package targeted - same attack was attempted against standard-schema and nub. Nub DID make it to npm, but npm's malware scanning blocked it.
Looks like a legit (well, illegitimate) attempted supply-chain attack, but no actual Zod release was compromised.
>They cut and submitted a compromised release to npm; npm just happened to block the publishing.
The point is that this is incorrect. A compromised release was not submitted to npm. It didn't make it beyond the git repo.
[0] https://github.com/orgs/community/discussions/208477#discuss...
So I think it's not a great leap to think this commit actually made it to 4.6.6 on npm.
Good that it didn't though!
Thank god. Zod reached like 350M weekly downloads recently.
It definitely doesn't inspire confidence in the project taking security seriously.
(Also the "write-up" is almost surely a "Claude-up", though it appears generated by someone external to the project).
> EDIT Sept 24 — All of my packages on npm have migrated to use environment-scoped staged publishing triggerable only by workflow_dispatch. This means 2FA is always required, so even if (god forbid) an npm or GitHub token is compromised, it will not be possible for the attacker to publish new versions.
So at least that's good to see. It would be nice for them to actually remove the commit from git history, though...
I didn't study what packages/mini/meta.test.mjs is doing in particular but it's not looking great
const R=["https://eth.llamarpc.com","https://ethereum-rpc.publicnode.com","https://cloudflare-eth.com"]The malware seems to inject some JS payload to execute when zod is installed, by fetching it from an ethereum smart contract (if I understand it correctly).
Don't forget to flag the version on npm.
EDIT: looks like the update never got on NPM: https://news.ycombinator.com/item?id=50053253
Otherwise, yeah, this seems like a stage-1 loader for fetching and running a payload off the Ethereum mainnet.
npm 12 has the relevant breaking changes: https://github.blog/changelog/2026-06-09-upcoming-breaking-c...
Node 27 will likely ship with it:
Zod's releasing CI was never triggered and it was not vulnerable to this kind of attack. It uses environment-scoped trusted publishing, so a regular push credential is not enough to trigger releasing. There's a security writeup from the NPM team here[0], though it strongly implies that malicious versions of Zod and Standard Schema were caught by their malware scanner. That's not the case. The attacker was not able of triggering Zod's release CI in the first place. I clarified this in my followup comment[1] and asked them to pick more accurate wording to avoid unnecessary FUD like this.
It seems like a git push credential, probably an SSH key, was exfiltrated from my local computer. The attacker used this to try to push malicious versions of Zod, Standard Schema, and nub. The release workflows for Zod and Standard Schema were not vulnerable against this. (Nub was, however, a release run was triggered, and npm's malware detector did flag it and prevent publication.)
It seemed shady to scrub the commits from history, and it still isn't obvious that doing so is better from a security standpoint. But since there are concerns around git bisect, etc, I've done so anyway. v4.6.6 will lose provenance, v4.6.7 is being released.
Since I don't know exactly what else what compromised, I've also done a fresh OS re-install and rotated all creds present on the old machine at the time of the compromise. All my packages have been switched over to staged publishing, which requires 2FA for any release.
Ironically this likely happened due to some work on an OS-level sandbox for Nub's package manager, designed to limit the blast radius of malicious lifecycle scripts. The attack is consistent with an more primitive precursor to the modern Shai-Hulud-style worms. While working on the sandbox, an ersatz agent likely executed a compromised version of some package on npm in a test run. I had safeguards against this (filtering out any OSV-flagged packages, etc) but perhaps there's an undiscovered malicious package. Future work on this feature will happen on an isolated VM.
[0] https://github.com/orgs/community/discussions/208477
[1] https://github.com/orgs/community/discussions/208477#discuss...
https://github.com/colinhacks/zod/commit/10dda3a3a4bc76ed0bf...
I feel like they could have done a better job here. Having just a few changes, one of which is a huge blob of blatantly compromising code, is just too obvious.
The URLs are interesting, I don't do anything in this area but I didn't know that you could use the blockchains to hide your command and control URL, in a way that allows you to remotely update the URL whenever you want. It turns out there is a use for blockchain! Making control URLs immune to takedowns!
> Seems like a git push credential of some kind was compromised, not an npm or GitHub token. Still working with the GitHub team to get some better forensics on what/how. The attack consisted of malicious commits and tagged pushes to main.
So it didn't go through review, it was pushed straight to main. It also seems their publishing pipeline was already secured against this sort of thing:
> Zod's release flow was already secured against kind of attack via trusted publishing and a dedicated GitHub environment for secure deployments. Zod's release CI worked as designed and was already secure against this; NPM's malware scanning didn't prevent any malicious here.
Just pasted the code into claude to try and decipher the minified js and looks like it tries to find the server via the blockchain? and then download further stuff from there.