extrahtmlPyPI
Advisory published Updated
extrahtml is a confirmed malicious PyPI package (MAL-2026-18771) that steals credentials and exfiltrates sensitive data (malicious versions 0.1.0, 0.1.1, 0.1.2). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in extrahtml (PyPI)
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):
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The malicious code is intentionally included in a dependency of the package
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Downloads and executes a remote malicious script.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for extrahtml (3 malicious versions).
If you installed it — respond
extrahtml 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 extrahtml 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
Campaign
References
Credits
- Kamil Mańkowski (kam193) · reporter
Detect & block this
O3 blocks extrahtml-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.