MAL-2026-18102

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/pypi/semveer/MAL-2026-18102.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-18102
Published
2026-10-20T18:20:32Z
Modified
2026-10-20T19:30:07Z
Summary
Malicious code in semveer (PyPI)
Details

-= Per source details. Do not edit below this line.=-

Source: amazon-inspector (d86237b957fd063a0e1fcf250a510b2fb9566ab48652e56fe787d2e1a02e351a)

The sdist for 'semveer' ships an inert module (semveer/init.py contains only a version stub) and places all runtime behavior inside setup.py's install hook. On pip install, setup.py calls urllib.request.urlretrieve against https://c2-worker.crawlnet-claim.workers.dev/dl/pyupd, writes the opaque payload to a temporary file, and launches it via subprocess.Popen with start_new_session=True as a detached process. The fetch is wrapped in a bare try/except that suppresses errors, there is no hash or signature verification, the version is not pinned, and the destination host is unrelated to any declared publisher or project homepage. The package name is a one-character edit of the widely used 'semver' name, consistent with a typosquat lure whose only purpose is to trigger the install-time dropper.

Source: kam193 (857ac41cf6480d83178766eebe04f79d075cc1f35be8b13b612c33b22e7ab434)

During installation, package downloads and executes malware.

Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.

Campaign: 2026-10-semvver

Reasons (based on the campaign):

  • Downloads and executes a remote executable.

  • malware

  • typosquatting

Database specific 
{
    "iocs":  {
        "domains":  [
            "c2-worker.crawlnet-claim.workers.dev"
        ],
        "urls":  [
            "https://c2-worker.crawlnet-claim.workers.dev/dl/pyupd"
        ]
    },
    "malicious-packages-origins":  [
        {
            "id":  "IN-MAL-2026-021536",
            "import_time":  "2026-10-20T18:22:19.853823457Z",
            "modified_time":  "2026-10-20T18:20:32Z",
            "sha256":  "d86237b957fd063a0e1fcf250a510b2fb9566ab48652e56fe787d2e1a02e351a",
            "source":  "amazon-inspector",
            "versions":  [
                "1.0.0"
            ]
        },
        {
            "id":  "pypi/2026-10-semvver/semveer",
            "import_time":  "2026-10-20T19:15:26.418202717Z",
            "modified_time":  "2026-10-20T18:28:46.433547Z",
            "sha256":  "857ac41cf6480d83178766eebe04f79d075cc1f35be8b13b612c33b22e7ab434",
            "source":  "kam193",
            "versions":  [
                "1.0.0"
            ]
        }
    ]
}
References
Credits

Affected packages

PyPI / semveer

Package

Name
semveer
View open source insights on deps.dev
Purl
pkg:pypi/semveer

Affected ranges

Affected versions

1.*
1.0.0

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":  "setup.py",
            "sha256":  "35decfc9dc81b7c7fa20816aa53e4d2fe2d2ed6b92c8a8780185eeee54e71c22",
            "tlsh":  "c5f0c052c517672a82c2c231ee2204632ff79603db83d8f4359c53545fcd97a8155e09"
        },
        {
            "path":  "semveer/__init__.py",
            "sha256":  "46c663463329acd7039bdef0a9145293aad32e04d7f0dd06ca2719c99f0eb014"
        }
    ],
    "package_integrity":  [
        {
            "filename":  "semveer-1.0.0.tar.gz",
            "hashes":  {
                "blake2b_256":  "65da67882f3ff16fc948ed5c857bd4d694bfaeaebd643af1aae6af16d74cc21c",
                "md5":  "643a6190861c62ab493552ab75890379",
                "sha256":  "d89c112e948539fb785a670d4a585e9a52cea2cf1d0c98db9e21fc29580ef281"
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/pypi/semveer/MAL-2026-18102.json"