MAL-2026-16128

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/pypi/pymem-win/MAL-2026-16128.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-16128
Published
2026-09-11T14:47:19Z
Modified
2026-09-11T23:30:06Z
Summary
Malicious code in pymem-win (PyPI)
Details

-= 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

Database specific 
{
    "iocs": {
        "urls": [
            "https://github.com/DreyCode2/youtube-downloader/releases/download/effe/clent.bin"
        ]
    },
    "malicious-packages-origins": [
        {
            "id": "pypi/2026-09-pymem-win/pymem-win",
            "import_time": "2026-09-11T15:17:36.016233836Z",
            "modified_time": "2026-09-11T14:47:19.131787Z",
            "sha256": "82eb1f11c9b56a2f2c3e97530db43ef94784a2c75697223828403927b0528477",
            "source": "kam193",
            "versions": [
                "1.14.0",
                "1.14.1",
                "1.14.4",
                "1.14.5",
                "1.14.6"
            ]
        },
        {
            "id": "IN-MAL-2026-020016",
            "import_time": "2026-09-11T23:15:30.496433375Z",
            "modified_time": "2026-09-11T22:40:49Z",
            "sha256": "4c611131ac135f4608698ce56eebd7dc89623b591510a050f2059369c9d51bbf",
            "source": "amazon-inspector",
            "versions": [
                "1.14.6"
            ]
        }
    ]
}
References
Credits

Affected packages

PyPI / pymem-win

Package

Name
pymem-win
View open source insights on deps.dev
Purl
pkg:pypi/pymem-win

Affected ranges

Affected versions

1.*
1.14.0
1.14.1
1.14.4
1.14.5
1.14.6

Database specific

cwes 
[
    {
        "cweId": "CWE-506",
        "description": "The product contains code that appears to be malicious in nature.",
        "name": "Embedded Malicious Code"
    }
]
indicators 
{
    "evidence_files": [
        {
            "path": "pymem/__init__.py",
            "sha256": "af96f169b2ee5499179f9acf16cdaf07add72feb19dbd28f6b32baa42bf4a72d",
            "tlsh": "5c232102de1dde5681c6c16530e18413cfd104db0a1d3a78b9fcd16a2feeab5c8bda5a"
        },
        {
            "path": "pyproject.toml",
            "sha256": "beffc3816b5e28f46f1ff800b961d427572c14a658b8b658f88f0f2af4418e49",
            "tlsh": "ef21e1138cce5d642e8365c5642914056d31a8173dcd608a77df828e9e9deef40f913d"
        }
    ],
    "package_integrity": [
        {
            "filename": "pymem_win-1.14.6-py3-none-any.whl",
            "hashes": {
                "blake2b_256": "9f08109e2087d3802a3c686af2e3055e1e6b5e44dd2de1d8876527c03019bc39",
                "md5": "e2861d59dedee16dfbc87aed41361613",
                "sha256": "eef73559e9e2c2eb277587ee8966760a04b262bb98bc93d02a0302de6f282ecb"
            }
        },
        {
            "filename": "pymem_win-1.14.6.tar.gz",
            "hashes": {
                "blake2b_256": "00413c4e1bd00140fbc1e2f1744bb0c77099ff993b8b19ae0d16997db3cff855",
                "md5": "a7ac1cfd6901620ef1d067dae0162c04",
                "sha256": "0bdec21a7ae4c23d38215df7ca650bfa6a81a185f302bd8a3f585c3ddcbb6c63"
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/pypi/pymem-win/MAL-2026-16128.json"