🛡️ MAL-2026-6276 — node-core-libs

Malicious code in node-core-libs (npm)

Source: amazon-inspector

scripts/postinstall.js runs automatically on npm install (Windows only) and behaves as a classic install-time dropper. It XOR-decodes (key 0x5A) a hardcoded host and port to produce node22.lunes.host:3258, performs an HTTP GET to http://node22.lunes.host:3258/nl, writes the response bytes to %TEMP%/ms_<rand>.js, and launches them via a generated wscript.exe //B //nologo <vbs> shim with detached:true and windowsHide. The destination is plain HTTP with no version pin, no hash verification, and no integrity check — any bytes the operator of node22.lunes.host returns are executed on the installer's machine. After dropping the payload the script self-cleans: a _tidy() routine rewrites the package's own package.json to remove scripts.postinstall and scripts.install, then unlinks the postinstall script itself, frustrating post-incident review. The script also writes %TEMP%/.nfc_root as a coordination marker and probes for a sibling package node-fetch-utils (a likely typosquat of node-fetch) referencing a node_launcher.js that patches lockfiles, indicating a multi-package campaign with persistence beyond this tarball. The XOR obfuscation of the C2 host, port, and a changeme-spectre key is deliberate concealment of the destination from registry scanners. Installer impact: running npm install node-core-libs on Windows results in arbitrary attacker-controlled code execution under the installing user's account.

Source: ghsa-malware

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.