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 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.

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?

Search your lockfiles and build artifacts for mpkg123 (version 0.0.0).

Malicious package

mpkg123PyPI

Advisory published May 11, 2026Updated May 11, 2026

mpkg123 is a confirmed malicious PyPI package (MAL-2026-3426) that steals credentials and exfiltrates sensitive data (malicious version 0.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in mpkg123 (PyPI)

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
Search your lockfiles and build artifacts for mpkg123 (version 0.0.0).
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 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

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

Explore

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