moonbit-schema-utilsPyPI
Malicious code in moonbit-schema-utils (PyPI) Remove it immediately and rotate any exposed credentials.
What this malware does
Campaign includes a chain of dependencies that finally exfiltrate sensitive environment variables to a hardcoded GitHub repository as exfiltration target, and in specific environments also start a reverse shell. It appears to be targeting specifically one GitHub project, where the front-end package was included in a PR.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-04-moonbit-locale-compat
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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The package contains code to create a reverse shell, allowing an attacker to execute any commands on the victim's machine.
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exfiltration-env-variables
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for moonbit-schema-utils (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging moonbit-schema-utils across your stack and pipelines.
If you installed it — respond
moonbit-schema-utils 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 moonbit-schema-utils 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 moonbit-schema-utils 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
Campaign
References
Credits
- Kamil Mańkowski (kam193) · reporter
Detect & block this
O3 blocks moonbit-schema-utils-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.