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Malicious package

cleanup-stringPyPI

Advisory published Updated

cleanup-string is a confirmed malicious PyPI package (MAL-2026-17325) that executes malicious code on install (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in cleanup-string (PyPI)

MAL-2026-17325
Immediate action
Remove the package, then rotate any secrets the build/runtime could reach.
pip uninstall cleanup-string

What this malware does

The package advertises itself as a pure-Python string helper (strip, slugify, case conversion, whitespace collapse) and its README states the implementation is standard-library only. However, cleanup_string/__init__.py performs from._impl import cleanup, which loads a 1.3 MB Windows-only native extension cleanup_string/_impl.cp313-win_amd64.vmp.pyd (sha256 980ae204f04f9a7e68666670eb5b236bc7347d0111697df1015de665fd1a1712). The filename embeds the VMProtect convention .vmp and the binary matches that packer's signature: the only readable strings are Win32 API imports (LoadLibraryA, GetModuleHandleA, HeapAlloc, DisableThreadLibraryCalls, ExitProcess, KERNEL32.dll, VCRUNTIME140.dll) and the remaining ~1.3 MB is high-entropy virtualized code. VMProtect exists to defeat static and dynamic analysis; the trivial advertised functionality has no legitimate need for a virtualized native module. Any Windows Python 3.13 environment that imports cleanup_string executes this opaque, anti-analysis-protected code with the privileges of the importing process.

Malicious versions

1 flagged
1.0.0

Indicators of compromise (SHA-256)

844c5afa9f00c02149f4f6314447c5738e04ed419014809c1df83f31aa012525

Detection & response playbook

Malicious package
  1. Find it

    Search your lockfiles and build artifacts for cleanup-string (version 1.0.0).

  2. If you installed it — respond

    Remove cleanup-string from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.

  3. Did it already run?

    If cleanup-string 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

No. cleanup-string on PyPI has been identified as a malicious package (version 1.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-020805

References

Credits

  • Amazon Inspector · finder

Detect & block this

O3 blocks cleanup-string-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.

Explore

cleanup-string (PyPI) malicious package — MAL-2026-17325 | O3 Security