temp-development-package-testPyPI
Malicious code in temp-development-package-test (PyPI) Remove it immediately and rotate any exposed credentials.
What this malware does
At install time, setup.py invokes install_sitecustomize(), which copies src/temp_development_package_test/setup/sitecustomize.py into Python's purelib site-packages directory as sitecustomize.py (setup.py:34 destination = site_packages / "sitecustomize.py"; setup.py:36 shutil.copy2(source, destination)). Python auto-imports sitecustomize on every interpreter startup, so this places an interpreter-wide hook outside the package's own namespace that fires for every subsequent Python process on the host — a classic persistence mechanism. The hook payload file is not actually shipped in this 0.2 sdist, so the install would currently raise FileNotFoundError, but the install-time mechanism and intent to write a global hook are unambiguous. The package metadata corroborates a throwaway / probe release: name, author, and summary are all the literal placeholder 'temp_development_package_test'; setup.py imports base64 but never uses it; cli.py imports from an unrelated, undeclared module 'pg_agent.orchestration.coordinator'. The combination — placeholder identity plus install-time write of a global interpreter hook — is not a legitimate package shape.
Starting with version 0.4, package installs a sitecustomize.py that executes during Python engine initialization. The embeded code uses mshta to download malicious code, as in other packages from the campaign.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-06-easyaillm
Reasons (based on the campaign):
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Downloads and executes a remote executable.
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obfuscation
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malware
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tool:mshta
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 temp-development-package-test (4 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging temp-development-package-test across your stack and pipelines.
If you installed it — respond
temp-development-package-test 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 temp-development-package-test 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 temp-development-package-test 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
- Amazon Inspector · finder
- Kamil Mańkowski (kam193) · analyst
Detect & block this
O3 blocks temp-development-package-test-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.