Which versions of mpkg123 are malicious?

The following PyPI versions of mpkg123 are flagged malicious: 0.0.0. Treat any of these as compromised.

How do I remediate mpkg123 if I installed it?

mpkg123 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 mpkg123 — how do I know if it already compromised me?

If mpkg123 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 mpkg123 part of a known attack campaign?

Yes — mpkg123 is associated with the 2026-05-old-mpkg123 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 mpkg123 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 mpkg123 (version 0.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging mpkg123 across your stack and pipelines.

Malicious package

mpkg123PyPI

Malicious code in mpkg123 (PyPI) Remove it immediately and rotate any exposed credentials.

MAL-2026-3426

Immediate action

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

pip uninstall mpkg123

What this malware does

If executed as a module, the obfuscated code collects and exfiltrates sensitive data, including passwords saved in a browser.

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

Campaign: 2026-05-old-mpkg123

Reasons (based on the campaign):

infostealer
obfuscation
A Telegram webhook is used to send collected data.
exfiltration-browser-data

Malicious versions

1 flagged

0.0.0

Indicators of compromise (SHA-256)

df9e0498d827adeb16ea11e4a1137133d2124f039942b776f7ac098a257cd164

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 mpkg123 (version 0.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging mpkg123 across your stack and pipelines.
If you installed it — respond
mpkg123 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 mpkg123 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 mpkg123 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. mpkg123 on PyPI has been identified as a malicious package (version 0.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

2026-05-old-mpkg123

References

bad-packages.kam193.eu

Credits

Kamil Mańkowski (kam193) · reporter

Detect & block this

O3 blocks mpkg123-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