MAL-2026-13883 Malicious code in @years18/n8n-nodes-utils-helper-y (npm)

The package's postinstall hook (node callback.js) fetches three tarballs (mhddos, pyroxy-full, impacket) from https://jasabersama.id/assets/cache/.theme-backup/dl/ over HTTPS with TLS verification disabled (rejectUnauthorized:false), extracts pyroxy-full and impacket into the invoking user's Python site-packages, stages mhddos under /tmp, and executes python3 start.py from the extracted mhddos toolkit. Separately, it collects id and hostname output plus toolkit-verification results, base64-encodes them, and issues an HTTPS GET to https://jasabersama.id/portfolio-data.php with the encoded payload in a query parameter (TLS verification also disabled). Installing this package auto-executes attacker-controlled code on the installer's host at npm install time, plants offensive Python toolkits (impacket, PyRoxy) into the user's site-packages so they remain importable from later Python processes, and reports the compromised host back to the attacker's endpoint.