🛡️ MAL-2026-12811 — ts-poly-utls

Malicious code in ts-poly-utls (npm)

Source: amazon-inspector

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.