Which versions of brotli-python are malicious?

The following PyPI versions of brotli-python are flagged malicious: 1.0.9, 1.1.9, 1.2.9, 1.9.12, 99.1.1, 99.2.1, 99.3.1, 99.5.1, 99.6.1, 99.99.1, 100.99.0. Treat any of these as compromised.

How do I remediate brotli-python if I installed it?

brotli-python 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 brotli-python — how do I know if it already compromised me?

If brotli-python 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 brotli-python part of a known attack campaign?

Yes — brotli-python is associated with the RLMA-2025-04748, GENERIC-standard-pypi-install-pentest, RLUA-2026-00155 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 brotli-python 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 brotli-python (11 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging brotli-python across your stack and pipelines.

Malicious package

brotli-pythonPyPI

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

MAL-2025-47749

Immediate action

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

pip uninstall brotli-python

What this malware does

Installing the package or importing the module exfiltrates basic information about the host, and the package has no other purpose.

Category: PROBABLY_PENTEST - Packages looking like typical pentest packages, but also anything that looks like testing, exploring pre-prepared kits, research & co, with clearly low-harm possibilities.

Campaign: GENERIC-standard-pypi-install-pentest

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.
The package overrides the install command in setup.py to execute malicious code during installation.

Malicious versions

11 flagged

1.0.91.1.91.2.91.9.1299.1.199.2.199.3.199.5.199.6.199.99.1100.99.0

Indicators of compromise (SHA-256)

2ec570a3bde8f9312ed5f031fd3423750dc7b1f6ac99506dbac2b5f3767e8c2e

65512240f27e9cf895a084968c506b54497be85127ec7d8da531eaf21fcb236a

3750f9d493198c7607b7f1d5855b6e8726edb24618beeb216e5a86a4a9119e5f

001d708d03d7eb0b5ceaed11cea3cfd3ff915e784393a872f5cf71d087dc04fd

b407cfd27f26faa22ea6f8f13e5551e2ee666aef52e7af04b9ed8f8e5feda8cf

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 brotli-python (11 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging brotli-python across your stack and pipelines.
If you installed it — respond
brotli-python 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 brotli-python 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 brotli-python 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. brotli-python on PyPI has been identified as a malicious package (versions 1.0.9, 1.1.9, 1.2.9, 1.9.12, 99.1.1, 99.2.1, 99.3.1, 99.5.1, and 3 more flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2025-04748GENERIC-standard-pypi-install-pentestRLUA-2026-00155

References

bad-packages.kam193.eu

Credits

Kamil Mańkowski (kam193)
ReversingLabs · finder

Detect & block this

O3 blocks brotli-python-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