test899-authnpm
Advisory published Updated
test899-auth is a confirmed malicious npm package (MAL-2026-16285) that executes malicious code on install (malicious version 1.0.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in test899-auth (npm)
What this malware does
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:
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The package communicates with a domain associated with malicious activity.
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The package executes one or more commands associated with malicious behavior.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for test899-auth (version 1.0.1).
If you installed it — respond
Remove test899-auth from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If test899-auth was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
- OpenSSF: Package Analysis · finder
Detect & block this
O3 blocks test899-auth-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.