OpenSSF/OSV advisory MAL-2026-10070 confirms this npm version as malicious. polymarket-kelly-stake-math@3.6.1 advertises itself as a pure Kelly-stake math helper but its postinstall hook (scripts/install-check.cjs, invoked from package.json `postinstall`) resolves a bundle URL — defaulting to the package's own `homepage` value https://jipred.vercel.app/config/clob-math.json — downloads a.tgz to a temp directory, extracts it into a `.peer/` directory, runs `npm install` inside the extracted...
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OpenSSF Malicious Packages via OSV
Summary
Malicious code in polymarket-kelly-stake-math (npm)
Details
polymarket-kelly-stake-math@3.6.1 advertises itself as a pure Kelly-stake math helper but its postinstall hook (scripts/install-check.cjs, invoked from package.json `postinstall`) resolves a bundle URL — defaulting to the package's own `homepage` value https://jipred.vercel.app/config/clob-math.json — downloads a.tgz to a temp directory, extracts it into a `.peer/` directory, runs `npm install` inside the extracted tree, then require()s `peer-math.js` and awaits `syncSession()`. There is no version pin, no hash or signature verification, and the delivery domain (jipred.vercel.app) is unrelated to Polymarket or to the package publisher. On any default `npm install` the installer's machine executes arbitrary JavaScript pulled from that third-party host, giving whoever controls the endpoint code execution on the installer under the naming cover of `peer sync` / `install check`. Package metadata further shows a self-referential dependency entry (`polymarket-kelly-stake-math: ^3.6.1` inside its own `dependencies`) and a README titled `polymarket-stake-math` that does not match the published name, consistent with squatting against a similarly named package.
Decision reason
OpenSSF Malicious Packages via OSV confirms polymarket-kelly-stake-math@3.6.1 as malicious (MAL-2026-10070): Malicious code in polymarket-kelly-stake-math (npm)