fastapiiPyPI
fastapii is a confirmed malicious PyPI package (MAL-2026-13486) that steals credentials and exfiltrates sensitive data (malicious versions 0.1.1, 0.1.2, 0.2.0…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in fastapii (PyPI)
What this malware does
fastapii 0.1.2 is a single-character typosquat of the popular fastapi package. Its setup.py registers a custom setuptools install cmdclass (LinuxInstall) whose post_install step decodes a base64-encoded payload (_HOOK_B64) and runs it via exec(compile(...)). On Linux, the decoded payload calls urllib.request.urlretrieve to fetch a binary from https://github.com/totti2188/8gp1Q7iZD3h4VW/releases/download/v1.3A/something into /tmp, chmods it to 0755, and launches it detached via subprocess.Popen with start_new_session=True. The GitHub account hosting the binary is unrelated to the package's declared identity, the fetch is unpinned and unverified (no hash or signature), and the Linux-only gate means the payload stays dormant on many developer laptops but fires in Linux CI and production. The shipped module is a stub named djangoo containing only a trivial hello() function, and PKG-INFO/README metadata ('HTTP client utilities', '# requestss') further obscure the package identity — the install-time dropper is the package's sole real behavior.
Package imitates name of a popula library. During installation, obfuscated code downloads a malicious executable and starts it. It then exfiltrates at least cryptocurrency wallet data, probably more.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-08-flasq
Reasons (based on the campaign):
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typosquatting
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The package overrides the install command in setup.py to execute malicious code during installation.
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exfiltration-generic
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Downloads and executes a remote executable.
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obfuscation
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exfiltration-crypto
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 fastapii (4 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging fastapii across your stack and pipelines.
If you installed it — respond
fastapii 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 fastapii 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 fastapii 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) · reporter
Detect & block this
O3 blocks fastapii-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.