my-private-pkgPyPI
Advisory published Updated
my-private-pkg is a confirmed malicious PyPI package (MAL-2026-17180) that steals credentials and exfiltrates sensitive data (malicious versions 0.1.1, 99.1.1, 99.11.2). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in my-private-pkg (PyPI)
What this malware does
Version 99.1.1 of my-private-pkg executes a custom setuptools install hook while a wheel is built. The hook launches my_private_pkg/index.py, which collects the current username, working directory, hostname, resolved local IP address, operating system, and machine architecture, then attempts to POST the resulting JSON to a hard-coded Webhook.site request collector. Dynamic analysis observed the wheel build spawn this script followed immediately by network activity. The package's public metadata describes it only as a private Python package and does not disclose the collection or transmission.
setup.py registers a custom install command (PostInstallCommand) that runs my_private_pkg/index.py automatically on pip install. That script gathers installer-side identifiers — os.getlogin(), socket.gethostname(), local IP address, os.getcwd(), platform.system() and platform.machine() — and POSTs them as JSON to a hardcoded collector URL at https://webhook.site/d4d1b01b-708a-40b9-b8c8-187eeecafeed. A duplicate of the exfiltration payload is shipped as vercel_runtime_python/index.py, and vercel_runtime_python/init.py contains the same PostInstallCommand wiring referencing my_private_pkg/index.py; the module name mimics Vercel's Python runtime. The package name and the internal vercel_runtime_python module name are consistent with a dependency-confusion lure targeting an internal my-private-pkg name and Vercel's runtime namespace: the only on-install effect is a reconnaissance beacon to an attacker-controlled webhook.site endpoint identifying the host that mistakenly resolved the public name.
Installing the package or importing the module exfiltrates basic information about the host, and the package has no other purpose.
Category: PROBABLY_PENTEST - Packages looking like typical pentest packages, but also anything that looks like testing, exploring pre-prepared kits, research & co, with clearly low-harm possibilities.
Campaign: GENERIC-standard-pypi-install-pentest
Reasons (based on the campaign):
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The package contains code to exfiltrate basic data from the system, like IP or username. It has a limited risk.
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The package overrides the install command in setup.py to execute malicious code during installation.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for my-private-pkg (3 malicious versions).
If you installed it — respond
my-private-pkg 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 my-private-pkg 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
Campaign
References
Credits
- Amazon Inspector · finder
- Kamil Mańkowski (kam193) · reporter
- smiling-hyena · finder
Detect & block this
O3 blocks my-private-pkg-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.