MAL-2026-10070 Malicious code in polymarket-kelly-stake-math (npm)

[email protected] 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.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.