Which versions of parseyaml are malicious?

The following PyPI versions of parseyaml are flagged malicious: 1.2.0. Treat any of these as compromised.

How do I remediate parseyaml if I installed it?

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

If parseyaml 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 parseyaml part of a known attack campaign?

Yes — parseyaml is associated with the 2026-11-parseyaml 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 parseyaml across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for parseyaml (version 1.2.0).

Malicious package

parseyamlPyPI

Advisory published Nov 8, 2026Updated Nov 8, 2026

parseyaml is a confirmed malicious PyPI package (MAL-2026-18772) that steals credentials and exfiltrates sensitive data (malicious version 1.2.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in parseyaml (PyPI)

MAL-2026-18772

Immediate action

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

pip uninstall parseyaml

What this malware does

In this campaign, remote code is executed via a dependency pretending to be a YAML loader but embedding a special loader executing code from a provided file. During analysis, the code was just a stub.

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

Campaign: 2026-11-parseyaml

Reasons (based on the campaign):

The malicious code is intentionally included in a dependency of the package
Downloads and executes a remote malicious script.

Malicious versions

1 flagged

1.2.0

Indicators of compromise (SHA-256)

21f0c643e1ed1b11c56bfdd5f7567b2c0172924c227206b8ab9e4210918c6ee3

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for parseyaml (version 1.2.0).
If you installed it — respond
parseyaml 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 parseyaml 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. parseyaml on PyPI has been identified as a malicious package (version 1.2.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

2026-11-parseyaml

References

bad-packages.kam193.eu

Credits

Kamil Mańkowski (kam193) · reporter

Detect & block this

O3 blocks parseyaml-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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