cfgzenPyPI
Advisory published Updated
cfgzen is a confirmed malicious PyPI package (MAL-2026-11094) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.0, 1.0.1, 1.0.2…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in cfgzen (PyPI)
What this malware does
The package installs a site-wide cfgzen.pth containing import dotcfg, which Python's site machinery executes automatically at every interpreter startup — turning every python invocation on the host into a trigger for the payload. On import, dotcfg/__init__.py spawns a detached background Python subprocess (env-gated with _CFGZ_BG=1 and CREATE_NO_WINDOW on Windows) that re-imports the package and calls _native.platform_check() in the shipped Windows PyO3 extension dotcfg/_native.pyd. The native module contains: a hardcoded anonymous file-drop endpoint at files.catbox.moe/7t4wyu.*; WinHTTP and raw ws2_32 socket primitives with a spoofed Mozilla Windows User-Agent; enumeration of host identifiers (COMPUTERNAME, HOSTNAME, USERNAME, USER, LOCALAPPDATA, TEMP) staged into a file named envcorecache.dat; a CI/sandbox-evasion fingerprint enumerating 14+ build-environment variables (GITHUB_ACTIONS, GITLAB_CI, JENKINS_HOME, TRAVIS, CIRCLECI, CODEBUILD_BUILD_ID, TF_BUILD, BUILDKITE, DRONE, APPVEYOR, CI, CONTINUOUS_INTEGRATION, TEAMCITY_VERSION, HEROKU_TEST_RUN_ID); and Microsoft-mimicry staging paths (Microsoft\EdgeUpdate\EdgeUpdateService.exe, Microsoft\WindowsApps\RuntimeBroker_v2.exe, Microsoft\Edge\Temp\msedge_installer.exe, Microsoft\MediaSync\MediaSyncAgent.exe, Microsoft\Provisioning\ProvisioningHost.exe). The combination —.pth-based persistence, hidden detached subprocess, host fingerprinting, dual HTTP/socket exfil transports to an anonymous file host, CI-evasion, and Edge/Update-mimicry file names — is a Windows stealer/dropper, not a .env parser.
The malicious code sits in a native module, which is called in a few places, including the code run via PTH embedded since version 1.0.6. The native module downloads an encrypted blob and decrypt it to an executable being an infostealer.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-07-cfgzen
Reasons (based on the campaign):
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infostealer
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exfiltration-env-variables
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Downloads and executes a remote executable.
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obfuscation
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The package contains code to detect if it is running in a sandbox environment.
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exfiltration-crypto
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native-extension
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persistence
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abuses-pth
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for cfgzen (7 malicious versions).
If you installed it — respond
cfgzen 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 cfgzen 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
Detect & block this
O3 blocks cfgzen-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.