uvhttp-customPyPI
uvhttp-custom is a confirmed malicious PyPI package (MAL-2026-15863) that steals credentials and exfiltrates sensitive data (malicious versions 1.7.9, 1.8.1, 1.9.9). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in uvhttp-custom (PyPI)
What this malware does
setup.py contains an obfuscated payload of the form (lambda __: exec(__import__('base64').b64decode('...').decode()))(None) alongside an otherwise-benign setuptools import. The decoded payload writes a bundled script.ps1 to disk and invokes powershell -ExecutionPolicy Bypass -File script.ps1. The PowerShell script uses System.Net.WebClient.DownloadFile to fetch a Windows executable from cdn.discordapp.com/attachments/1532996358427115552/1539384056284717066/enlisted_launcher_1.0.3.190-movn8hpfe.exe into %TEMP%\file.exe and launches it via Start-Process with -WindowStyle Hidden. No hash or signature verification is performed. The payload also invokes os.system("calc"). Running pip install uvhttp-custom on Windows therefore causes the installer's machine to download and silently execute an opaque, unsigned binary from an anonymous Discord CDN URL.
During installation, obfuscated code downloads and executes an executable. It appears to be a game launcher.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-09-uvhttp-custom
Reasons (based on the campaign):
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The package overrides the install command in setup.py to execute malicious code during installation.
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Downloads and executes a remote executable.
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obfuscation
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 uvhttp-custom (3 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging uvhttp-custom across your stack and pipelines.
If you installed it — respond
uvhttp-custom 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 uvhttp-custom 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 uvhttp-custom 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 uvhttp-custom-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.