Vulnerability-Lookup

MAL-2026-17164

Vulnerability from ossf_malicious_packages

Published

2026-09-24 14:53

Modified

2026-09-24 14:53

Summary

Malicious code in building-build (npm)

Details

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

Source: amazon-inspector (4618f06d0398ff90ef90003464e79f23609a160f4d1606f60cf797fb73fa6dcb)

The package's sole content is index.js, which on load schedules a timer that fetches a hardcoded list of privileged same-origin paths (/admin, /dashboard, /flag, /api/flag, /secret, /admin/flag) and POSTs each response body to /addPost as JSON of the form {content: path + '::' + body}. When bundled into a web application, this abuses the ambient session of whichever authenticated user loads the bundle to read privileged routes and relay the contents to the site's posting endpoint. package.json has empty description, author, and keywords, no exports, and the name 'building-build' bears no relation to the shipped behavior — the package has no library surface and exists only to deliver this payload.

CWE

CWE-506 - The product contains code that appears to be malicious in nature.

Credits

Amazon Inspector inspector-research@amazon.com

JSON

To clipboard

{
  "affected": [
    {
      "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": "index.js",
              "sha256": "34fe4cabacfb8e464ebf6ccfa859751ebf78d3ca883ac6cf9d2feccef8f2de55",
              "tlsh": "75f02b8e7eb526069627e03f4a2ff104663b7447644ac950bd9c458a4fa8248aed69cc"
            },
            {
              "path": "package.json",
              "sha256": "43218da1c8ba116ae3f045fd9d2b78bb18b916eb4bdaf3889c786b966c329b19",
              "tlsh": "78d05e240a22583316c152221e259152b2208e6f00807c08529f181c429f67269f9308"
            }
          ],
          "package_integrity": [
            {
              "filename": "building-build-1.0.0.tgz",
              "hashes": {
                "sha1": "b4796c5656263cf805b054ef0515979eaf77be8e",
                "sha512_sri": "sha512-Aaq3YbcxCVeM6Bp5xxIlD2g59ExePgE4sVd4unablbaZkIkf2C52cFsfr4aoPl9YnezM2YG/mg9TVutAfVupPQ=="
              }
            }
          ]
        }
      },
      "package": {
        "ecosystem": "npm",
        "name": "building-build"
      },
      "versions": [
        "1.0.0"
      ]
    }
  ],
  "credits": [
    {
      "contact": [
        "inspector-research@amazon.com"
      ],
      "name": "Amazon Inspector",
      "type": "FINDER"
    }
  ],
  "database_specific": {
    "malicious-packages-origins": [
      {
        "id": "IN-MAL-2026-020516",
        "import_time": "2026-09-24T15:18:49.859933657Z",
        "modified_time": "2026-09-24T14:53:06Z",
        "sha256": "4618f06d0398ff90ef90003464e79f23609a160f4d1606f60cf797fb73fa6dcb",
        "source": "amazon-inspector",
        "versions": [
          "1.0.0"
        ]
      }
    ]
  },
  "details": "\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (4618f06d0398ff90ef90003464e79f23609a160f4d1606f60cf797fb73fa6dcb)\nThe package\u0027s sole content is index.js, which on load schedules a timer that fetches a hardcoded list of privileged same-origin paths (/admin, /dashboard, /flag, /api/flag, /secret, /admin/flag) and POSTs each response body to /addPost as JSON of the form {content: path + \u0027::\u0027 + body}. When bundled into a web application, this abuses the ambient session of whichever authenticated user loads the bundle to read privileged routes and relay the contents to the site\u0027s posting endpoint. package.json has empty description, author, and keywords, no exports, and the name \u0027building-build\u0027 bears no relation to the shipped behavior \u2014 the package has no library surface and exists only to deliver this payload.\n",
  "id": "MAL-2026-17164",
  "modified": "2026-09-24T14:53:06Z",
  "published": "2026-09-24T14:53:06Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://www.npmjs.com/package/building-build/v/1.0.0"
    }
  ],
  "schema_version": "1.7.4",
  "summary": "Malicious code in building-build (npm)"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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