internallib_v550npm
Advisory published Updated
internallib_v550 is a confirmed malicious npm package (MAL-2026-16439) 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 internallib_v550 (npm)
What this malware does
Package internallib_v550 is named to resemble an internal private library and is published to the public npm registry, matching the classic dependency-confusion squat pattern. Its package.json description is 'pwn'. The single exported function command invokes child_process.exec to spawn /bin/bash -c id and logs the string 'infected' on the consumer host. The payload does not run at install or import time; it fires when consumer code calls the exported function. The name-squat intent, self-labeling as 'pwn', and shell-out on the exported API together form a dependency-confusion attack payload rather than a legitimate library.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for internallib_v550 (version 1.0.1).
If you installed it — respond
Remove internallib_v550 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 internallib_v550 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
Detect & block this
O3 blocks internallib_v550-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.