MAL-2026-16285 Malicious code in test899-auth (npm)

On npm install, the package's preinstall hook executes index.js which collects installer host and identity information (hostname, platform, OS release, whoami, id, current working directory, uname -a), base64-encodes the blob, splits it into DNS labels, and issues nslookup queries against the hardcoded subdomain hufw8vt7sk2vw016qzzgek9gr7x0ls9h.oastify.com. This tunnels installer identity and host details out-of-band via DNS to a Burp Collaborator endpoint, bypassing HTTP egress filtering. The package.json also declares a self-referential unpinned dependency on test899-auth: ^1.0.1, consistent with a probing/PoC harness shape. The name and behavior are consistent with a research or malicious probe package rather than a functional authentication library.

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.

The OpenSSF Package Analysis project identified 'test899-auth' @ 1.0.1 (npm) as malicious.

It is considered malicious because:

• The package communicates with a domain associated with malicious activity.

• The package executes one or more commands associated with malicious behavior.