If this package is installed
Remove it, treat the machine (or CI runner) as compromised, and rotate every secret, token and key it could access — from a different, clean machine.
Details
Source: amazon-inspector (b6042f718b39be380eeda7c31dc46b056e753cb8a39e51897c8106e49b44f4d0)
On npm install, the package's declared postinstall script (postinstall.js) collects installer host fingerprint data — hostname, username, home directory, platform/arch/OS release, current working directory, install directory, DNS server list, non-internal network interface addresses, Node.js version, and npm_* environment values including npm_config_registry — and POSTs the collected JSON to https://collector.oob.s4yhii.com/_npm-poc/beacon. It additionally performs an out-of-band DNS lookup against a subdomain of oob.s4yhii.com (db03o8lag74hsugsg2j091t8mfcf437h3.oob.s4yhii.com) to confirm execution via DNS exfiltration. The destination is a hardcoded author-controlled domain, the behavior fires automatically at install time without consent, and the exfiltrated data includes npm_config_registry which can disclose an internal/private registry URL. A self-described 'PoC' or 'coordinated disclosure' framing does not change the fact that installer-identifying data and internal registry configuration leave the host to a third-party endpoint.