Malicious code in workalender (PyPI)

{
  "id": "a54976f283ba8470563c0a9f4b7527a5692c1a5510f675158e2ce7a4ff634c80",
  "url": "https://osv.dev/vulnerability/MAL-2026-18096",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Malicious code in workalender (PyPI)",
    "summary": "--- _-= Per source details. Do not edit below this line.=-_ ## Source: kam193 (bb4f2824499fd64a22d9dfdb23c454bbb8797422f5281fdd5f454ea64095853a) Installing the package or importing the module exfiltrates basic information about the host, and the package has no other purpose. --- Category: PROBABLY_PENTEST - Packages looking like typical pentest packages, but also anything that looks like testing, exploring pre-prepared kits, research & co, with clearly low-harm possibilities. Campaign: GENERIC-standard-pypi-install-pentest Reasons (based on the campaign): - The package contains code to exfiltrate basic data from the system, like IP or username. It has a limited risk. - The package overrides the install command in setup.py to execute malicious code during installation.",
    "evidence": "osv:MAL-2026-18096",
    "products": [
      {
        "name": {
          "value": "workalender",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "17.1.0.dev0",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "MAL-2026-18096",
      "aliases": [
        "MAL-2026-18096"
      ],
      "affected": [
        {
          "package": {
            "name": "workalender",
            "purl": "pkg:pypi/workalender",
            "ecosystem": "PyPI"
          },
          "versions": [
            "17.1.0.dev0"
          ],
          "database_specific": {
            "source": "https://github.com/ossf/malicious-packages/blob/main/osv/malicious/pypi/workalender/MAL-2026-18096.json"
          }
        }
      ],
      "modified": "2026-10-20T14:30:03.703176593Z",
      "provider": "osv",
      "references": [
        "https://bad-packages.kam193.eu/pypi/package/workalender"
      ],
      "provider_metadata": {
        "malicious-packages-origins": [
          {
            "id": "pypi/GENERIC-standard-pypi-install-pentest/workalender",
            "sha256": "bb4f2824499fd64a22d9dfdb23c454bbb8797422f5281fdd5f454ea64095853a",
            "source": "kam193",
            "versions": [
              "17.1.0.dev0"
            ],
            "import_time": "2026-10-20T14:18:32.482923489Z",
            "modified_time": "2026-10-20T13:36:14.492931Z"
          }
        ]
      }
    },
    "related_cves": [],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 389090,
  "published_at": "2026-10-20T13:36:11+00:00"
}