mal-2026-18599

{
  "affected": [
    {
      "database_specific": {
        "cwes": [
          {
            "cweId": "CWE-506",
            "description": "The product contains code that appears to be malicious in nature.",
            "name": "Embedded Malicious Code"
          },
          {
            "cweId": "CWE-506",
            "description": "The product contains code that appears to be malicious in nature.",
            "name": "Embedded Malicious Code"
          }
        ],
        "indicators": {
          "evidence_files": [
            {
              "path": "script.rb",
              "sha256": "1a9aaf4ada6ff1225a0c9066bcc9ba27f91ce8eaf928fcfed5e32939e21a4f89",
              "tlsh": "dc4142725cc14d7b67e0e4483e2c1550f762614fc70418703aad426a2f65d3ba2b5bfb"
            }
          ],
          "package_integrity": [
            {
              "filename": "w002yardprobe-0.0.4.gem",
              "hashes": {
                "sha256": "2c92205c8a1ecbffe953de63a4308e7de19bff714f6b01a67f1780bd38f39794"
              }
            }
          ]
        },
        "source": "https://github.com/ossf/malicious-packages/blob/main/osv/malicious/rubygems/w002yardprobe/MAL-2026-18599.json"
      },
      "package": {
        "ecosystem": "RubyGems",
        "name": "w002yardprobe",
        "purl": "pkg:gem/w002yardprobe"
      },
      "versions": [
        "0.0.4",
        "0.0.5"
      ]
    }
  ],
  "credits": [
    {
      "contact": [
        "inspector-research@amazon.com"
      ],
      "name": "Amazon Inspector",
      "type": "FINDER"
    }
  ],
  "database_specific": {
    "malicious-packages-origins": [
      {
        "id": "IN-MAL-2026-022534",
        "import_time": "2026-11-04T03:13:46.189246589Z",
        "modified_time": "2026-11-04T02:58:29Z",
        "sha256": "5252a1d5dd27d6e0edd3c1fc3936ff09d93b2fcc8e5544afc09fe7fb7d90bee5",
        "source": "amazon-inspector",
        "versions": [
          "0.0.4"
        ]
      },
      {
        "id": "IN-MAL-2026-022533",
        "import_time": "2026-11-04T03:13:46.098494137Z",
        "modified_time": "2026-11-04T02:58:21Z",
        "sha256": "721580f8eda44ad5ee7604f5ba0648e8830302f784e3e4a995e02ca7359c909e",
        "source": "amazon-inspector",
        "versions": [
          "0.0.5"
        ]
      }
    ]
  },
  "details": "\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (721580f8eda44ad5ee7604f5ba0648e8830302f784e3e4a995e02ca7359c909e)\nThe gem ships a `.yardopts` file containing `--load./script.rb`, which causes YARD to execute `script.rb` whenever documentation is generated for the gem (locally via `yard doc`, in CI, or on doc-hosting services such as RubyDoc.info). `script.rb` collects host identifiers — `Socket.gethostname`, current working directory, UID, and `RUBY_VERSION` — and POSTs them via `Net::HTTP.post_form` to the hardcoded third-party collector `https://webhook.site/97fa3c6a-3fad-4d2d-8312-15dc37e41e66`. The same script also rewrites `lib/w002yardprobe.rb` in place (substituting a `MARKSLOT` token with a runtime stamp) and drops sentinel files `W002SCRIPT_RAN.txt` and `W002EGRESS_OK.txt` in the detected build directory (e.g. `/build`), indicating the gem is instrumented to probe a documentation-build sandbox. The package self-identifies as a probe; the exfiltration and build-environment mutation are the gem's purpose. The trigger is YARD doc generation rather than `gem install` or `require`, so the harm materializes against whichever host (developer workstation, CI runner, or doc-hosting pipeline) processes the gem's documentation.\n",
  "id": "MAL-2026-18599",
  "modified": "2026-11-04T03:30:03.195537037Z",
  "published": "2026-11-04T02:58:21Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://rubygems.org/gems/w002yardprobe/versions/0.0.4"
    },
    {
      "type": "PACKAGE",
      "url": "https://rubygems.org/gems/w002yardprobe/versions/0.0.5"
    }
  ],
  "schema_version": "1.9.2",
  "summary": "Malicious code in w002yardprobe (RubyGems)"
}