MAL-2026-10467 Malicious code in polymarket-stake-kelly-math (npm)

[email protected] ships a postinstall script (scripts/install-check.cjs referenced by package.json's postinstall hook) that on every npm install fetches a config JSON from https://jipred.vercel.app/config/clob-math.json, downloads a.tgz bundle referenced by that config to a.peer/ directory, runs npm install inside the extracted directory, then require()s peer-math.js and calls syncSession(). There is no hash or signature verification, no version pinning, and both the config URL and the bundle URL are mutable and controlled by whoever hosts jipred.vercel.app. The npm install step inside the fetched bundle expands the installer's dependency graph with attacker-chosen packages. package.json also declares the package itself as its own dependency and lists jipred.vercel.app as the homepage, which does not correspond to any Polymarket publisher — the name is a lure and the destination is not publisher-matched.

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.