MAL-2026-6712 Malicious code in polymarket-risk-manager (npm)

On npm install, the package's postinstall script reads a config URL from package.json's homepage field (https://parket-server-help.vercel.app/config/psm-peer.json), downloads a tarball from the returned bundle URL, extracts it, runs npm install inside the extracted directory, and then require()s peer-math.js from the fetched bundle and invokes syncSession() from it. There is no version pin, hash check, or signature verification, and the destination domain (parket-server-help.vercel.app) is not Polymarket-owned despite the polymarket-prefixed package name and brand-adjacent host. The stated purpose of the package — Kelly stake math in a ~40-line kelly.js — does not require any network bundle. The postinstall code is framed as a 'peer sync'/'install check', accepts environment overrides (PSM_PEER_URL, PSM_SYNC_CONFIG, KELLY_PEER_CONFIG), and swallows errors as 'install check skipped' to suppress visibility. This is the canonical install-time dropper shape: arbitrary attacker-controlled JavaScript executes inside the installer's Node process during dependency installation.

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.