Which versions of jsonschema-utf8 are malicious?

The following PyPI versions of jsonschema-utf8 are flagged malicious: 4.1.0, 4.1.1, 4.1.2. Treat any of these as compromised.

How do I remediate jsonschema-utf8 if I installed it?

jsonschema-utf8 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 jsonschema-utf8 — how do I know if it already compromised me?

If jsonschema-utf8 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 jsonschema-utf8 part of a known attack campaign?

Yes — jsonschema-utf8 is associated with the 2025-12-loguru-utf8 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 jsonschema-utf8 across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for jsonschema-utf8 (3 malicious versions).

Malicious package

jsonschema-utf8PyPI

Advisory published Dec 10, 2025Updated Dec 31, 2025

jsonschema-utf8 is a confirmed malicious PyPI package (MAL-2025-192436) that steals credentials and exfiltrates sensitive data (malicious versions 4.1.0, 4.1.1, 4.1.2). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in jsonschema-utf8 (PyPI)

MAL-2025-192436

Immediate action

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

pip uninstall jsonschema-utf8

What this malware does

Package clones a popular package (loguru, jsonschema, ...). While it claims to have some additional features, the real change is an added compiled native library which is silently loaded in the background during the importing of the module. The exact behavior is unknown, but the binary is obfuscated

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

Campaign: 2025-12-loguru-utf8

Reasons (based on the campaign):

clones-real-package
obfuscation
typosquatting
native-extension

Malicious versions

3 flagged

4.1.04.1.14.1.2

Indicators of compromise (SHA-256)

61bf4fa82a7c398e580d547d641bc19e3b16ba446191da04f39dcf9cf9a41eab

bae3458837c96ae1b3f9232719b712ca6d110a5c24099baf6c378977fa90062c

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for jsonschema-utf8 (3 malicious versions).
If you installed it — respond
jsonschema-utf8 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 jsonschema-utf8 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. jsonschema-utf8 on PyPI has been identified as a malicious package (versions 4.1.0, 4.1.1, 4.1.2 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

2025-12-loguru-utf8

References

Credits

Kamil Mańkowski (kam193) · reporter

Detect & block this

O3 blocks jsonschema-utf8-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

All malware advisories How O3 detects malware Vulnerability database