authmatrixnpm
authmatrix is a confirmed malicious npm package (MAL-2026-6656) that executes malicious code on install (malicious versions 1.0.30, 1.1.7). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in authmatrix (npm)
What this malware does
The package is published as 'authmatrix' with a description suggesting basic auth functionality, but its lib/ tree is a copy of the pino logger and its entry point auth.js requires lib/writer.js. At module top level, writer.js attempts require('ssr-auth-sync') and, on failure, shells out via execSync to run npm install ssr-auth-sync and then requires the just-installed module from a relative path. ssr-auth-sync is not declared in the package's dependencies, so any consumer that imports authmatrix triggers an unattended install and immediate execution of code from a third-party package name the installer never opted into. writer.js additionally hides its failure-path string by assembling it via String.fromCharCode concatenation rather than a literal, a low-grade evasion that co-occurs with the dropper path. The misleading auth-themed identity over a copy of pino, combined with the require-time fetch+execute of an undeclared external package, is a supply-chain dropper pattern.
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.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for authmatrix (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging authmatrix across your stack and pipelines.
If you installed it — respond
Remove authmatrix 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 authmatrix was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks authmatrix before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks authmatrix-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.