Which versions of license-checker are malicious?

The following PyPI versions of license-checker are flagged malicious: 0.1.2, 0.1.3. Treat any of these as compromised.

How do I remediate license-checker if I installed it?

license-checker is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed license-checker — how do I know if it already compromised me?

If license-checker 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.

Is license-checker part of a known attack campaign?

Yes — license-checker is associated with the RLMA-2025-04789, 2025-08-import-license-checker, RLUA-2026-00474 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find license-checker across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for license-checker (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging license-checker across your stack and pipelines.

Malicious package

license-checkerPyPI

Malicious code in license-checker (PyPI) Remove it immediately and rotate any exposed credentials.

MAL-2025-47784

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

pip uninstall license-checker

What this malware does

Package exfiltrates content of .env files to a remote target

Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.

Campaign: 2025-08-import-license-checker

Reasons (based on the campaign):

The package contains code to exfiltrate basic data from the system, like IP or username. It has a limited risk.

Malicious versions

2 flagged

0.1.20.1.3

Indicators of compromise (SHA-256)

967e4afc2b0d203a13486662f0a873d46b929c24c43ad4a16f012019d672ba1f

abb0589091e6ac57e231df47a1b8526b75f395d47517f3e49f0f87d5562c8207

a636a791b9731fe5018309c2e7890934873ab4c091520d933029f170a1848592

fc98590c31c34aa78ff1b312ccb42355720a16ba51fa84df3296c22152df10b4

e870a33b1a087a64a1ee6c04abf0ce08783addd61b28be459a02ac3d68422cd8

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for license-checker (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging license-checker across your stack and pipelines.
If you installed it — respond
license-checker is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If license-checker 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 license-checker 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

No. license-checker on PyPI has been identified as a malicious package (versions 0.1.2, 0.1.3 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2025-047892025-08-import-license-checkerRLUA-2026-00474

References

bad-packages.kam193.eu

Credits

Kamil Mańkowski (kam193)
ReversingLabs · finder

Detect & block this

O3 blocks license-checker-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring