MAL-2026-5763 Malicious code in npm-sandbox-research-g3h4 (npm)

On install, package.json's postinstall hook executes run.js. The package ships beacon15.js and beacon_linux.js, which import child_process, os, and http and issue outbound HTTP requests carrying host identifiers. beacon_linux.js reads os.hostname() and os.platform() and POSTs them via http.request(); beacon15.js similarly issues GET/http.request() calls referencing host id fields. The combination of a lifecycle hook that runs on every install plus modules that collect host metadata and beacon it outbound matches an install-time host-exfiltration / C2 callback pattern with no legitimate documented purpose.

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.