pymem-win (PyPI) · Malicious Code
Affects pymem-winSource GCVE Database
Malicious package : remove pymem-win and rotate any secrets on hosts that installed it.
Data as of 14 Sep 2026, 00:46 UTC
Malicious package
Published to PyPI · OSV MAL-2026-16128
What to do
Remove pymem-win from every project, lockfile and image that pulls it in. Treat any host that installed it as compromised: rotate the credentials, tokens and keys it could read, from a clean machine.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| PyPIpymem-win | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (4c611131ac135f4608698ce56eebd7dc89623b591510a050f2059369c9d51bbf) Pymem-win is a near-verbatim copy of the legitimate upstream Pymem package (reusing its description, repository URL github.com/srounet/Pymem, and author identity Fabien Reboia <srounet@gmail.com>) republished under a confusable name. The top-level pymem/__init__.py contains a one-line loader that reverses a bytes literal, base64-decodes it, zlib-decompresses it, and passes the result to exec(). This runs unconditionally on `import pymem`, handing full in-process code execution to a payload deliberately hidden behind three stacked transforms. The multi-layer obfuscation around an exec target has no legitimate purpose in a library import path; combined with the typosquat cover story that reuses the upstream author's identity, the package's function on install/import is to run attacker-chosen code inside any process that imports it. ## Source: kam193 (82eb1f11c9b56a2f2c3e97530db43ef94784a2c75697223828403927b0528477) During import, the obfuscated code downloads and executes an executable. The remote executable did not exist during analysis, but the repository used to host it overlaps with previous campaign 2026-07-yt-api-dlp --- Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers. Campaign: 2026-09-pymem-win Reasons (based on the campaign): - obfuscation - Downloads and executes a remote executable. - clones-real-package