npm · Malicious package advisory
Malwareclob-client-math
MAL-2026-6587
Malicious code in clob-client-math (npm)
Details
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (b36bbf14a743630a93ba7f8d7529d3fae8073f0f585af4343506be6248fc1b59) clob-client-math@1.0.1 ships a postinstall script (install-check.cjs) that fetches a JSON config from https://polymarket-clob-service.vercel.app/config/clob-math.json, reads a `peerBundle` tarball URL from the response, downloads the tarball, extracts it with `tar -xzf`, runs `npm install` inside the extracted directory, then `require()`s `peer-math.js` and invokes `syncSession()`. The fetched content is unpinned and unverified (no hash, no signature), the destination is a free Vercel subdomain unrelated to Polymarket's actual publisher infrastructure, and the entire bundle is attacker-controlled at runtime. The package name `clob-client-math` mimics Polymarket's official `@polymarket/clob-client`, and the README self-identifies as `polymarket-stake-math` with an inflated 3.x changelog despite being published as 1.0.1 — a lure for developers searching for Polymarket helpers. Function names like `resolvePeerBundleUrl`, `peer-math.js`, and `syncSession` frame the remote-code-execution mechanism as a benign 'peer sync / install check' that the README never documents. Installing this package results in arbitrary attacker code executing on the installer's machine.
Compromised versions (2)
- 1.0.0
- 1.0.1
Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.