Which versions of ts-poly-utls are malicious?

The following npm versions of ts-poly-utls are flagged malicious: 1.2.4. Treat any of these as compromised.

How do I remediate ts-poly-utls if I installed it?

Remove ts-poly-utls from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.

I already installed ts-poly-utls — how do I know if it already compromised me?

If ts-poly-utls was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Is ts-poly-utls part of a known attack campaign?

Yes — ts-poly-utls is associated with the IN-MAL-2026-014978 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find ts-poly-utls across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for ts-poly-utls (version 1.2.4).

Malicious package

ts-poly-utlsnpm

Advisory published Aug 5, 2026Updated Aug 5, 2026

ts-poly-utls is a confirmed malicious npm package (MAL-2026-12811) that executes malicious code on install (malicious version 1.2.4). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in ts-poly-utls (npm)

MAL-2026-12811

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall ts-poly-utls

What this malware does

The package's postinstall script (scripts/install-check.cjs) reads a bundle URL from https://polymarket-clob-service.vercel.app/config/clob-math.json, downloads the referenced.tgz to a temp directory, extracts it, runs npm install inside the extracted tree, then require()s peer-math.js from it and invokes syncSession() at install time. The remote payload is unpinned, has no hash or signature verification, and is hosted on a mutable third-party Vercel personal deployment not owned by Polymarket. Package identity also mismatches its own documentation: the published npm name is ts-poly-utls while the README self-describes as clob-math-v2 and instructs users to npm install clob-math-v2, and the homepage points to the same Vercel host that serves the payload URL rather than polymarket.com. Running npm install ts-poly-utls results in execution of attacker-controlled code on the installer's machine.

Malicious versions

1 flagged

1.2.4

Indicators of compromise (SHA-256)

5b4393db175757c3875327bbe006eb3b34e669ed8c899b9b1e482d93caeed7e8

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for ts-poly-utls (version 1.2.4).
If you installed it — respond
Remove ts-poly-utls from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If ts-poly-utls was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Frequently asked questions

No. ts-poly-utls on npm has been identified as a malicious package (version 1.2.4 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-014978

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks ts-poly-utls-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.

Malware detection Runtime egress monitoring

Explore

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