MAL-2026-5760 Malicious code in npm-sandbox-research-c5d6 (npm)

The package declares a postinstall hook ("postinstall": "node run.js") that executes automatically on npm install. The shipped beacon scripts (beacon11.js, beacon_linux.js) load child_process, os, and http, read host identifiers via os.hostname() and os.platform(), and issue outbound HTTP GET/POST requests carrying that data. This is the install-time host-fingerprinting and exfiltration shape: lifecycle execution + system-info collection + outbound network in a single chain, with no legitimate library functionality justifying the behavior.

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.