Malicious code in @user-services/web-components (npm)

{
  "id": "c5e6fd0431c9eb9b6ceb3b2b48985c45416880b835305b4ad203d2332ccb792c",
  "url": "https://osv.dev/vulnerability/MAL-2026-16379",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Malicious code in @user-services/web-components (npm)",
    "summary": "--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (02523ee1cb3bbb9119054ec3ed14ffc62d0d33ae3bd44dc29312c772cdba106b) @user-services/web-components@9.9.10 fires a hidden telemetry probe on both the npm install lifecycle (`node index.js`) and on every `require()` of the module. The probe in probe/impl.js reads os.userInfo().username, os.hostname() and the basename of process.cwd(), concatenates them with a prefix `uswc` and a timestamp into a subdomain of `oob.algamil7x.xyz`, and issues a `dns.resolve4` query — the query name itself is the exfiltration channel, delivering installer identity to the attacker-controlled authoritative nameserver. The exfil pipeline is deliberately hidden from static analysis: supporting modules (b8d6e3.js, c9e7f4.js) reconstruct the strings `os`, `dns`, `process`, `userInfo`, `hostname`, `cwd`, `resolve4` and the destination host `oob.algamil7x.xyz` from `String.fromCharCode` byte arrays, and load the `os` and `dns` core modules via `module.constructor._load(...)` instead of a static `require`. The destination host is not the declared homepage and is not documented anywhere in the package. The scope `@user-services` and its placeholder repository/author metadata (`github.com/user-services/web-components`, `eng@user-services.dev`) are generic and consistent with a dependency-confusion lure aimed at organisations with an internal `@user-services/*` scope. ## Source: ghsa-malware (a26643867a117b96b0d18cd07cbec2dbc",
    "evidence": "osv:MAL-2026-16379",
    "products": [
      {
        "name": {
          "value": "@user-services/web-components",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "9.9.10",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "MAL-2026-16379",
      "aliases": [
        "GHSA-f3g4-6hpx-9mcq",
        "MAL-2026-16379"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "@user-services/web-components",
            "purl": "pkg:npm/%40user-services/web-components",
            "ecosystem": "npm"
          },
          "versions": [
            "9.9.10"
          ],
          "database_specific": {
            "cwes": [
              {
                "name": "Embedded Malicious Code",
                "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."
              }
            ],
            "source": "https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/@user-services/web-components/MAL-2026-16379.json",
            "indicators": {
              "evidence_files": [
                {
                  "path": "runtime/support/telemetry/probe/impl.js",
                  "tlsh": "78119c5ab253d08f23c04695391c43e1882ec2d087cd10d1bbbc279ba28d7914ad3a66",
                  "sha256": "303e024d53affd063c83f1f13df4d0cfd14754e462e96d1ccd4ebc4b0e8ebb00"
                },
                {
                  "path": "runtime/support/telemetry/probe/c9e7f4.js",
                  "tlsh": "e9e0201b219fe14fa6d85ea73f17c5dac8420900e21d8ad9fa1d4787106a406c0c0770",
                  "sha256": "8abb9d677003e4dbdfe9ed14dc47eca3b9023a66c935989b593ba61d1b58e5cf"
                },
                {
                  "path": "package.json",
                  "tlsh": "ef110821856394331ad03ba09d76284b73a74856cde2bc0c17f7592483ced9a10fe37a",
                  "sha256": "554de13e4624f1bbdd4ef2a958dcbff646058685492ba1f458c2c8f4d4950cce"
                }
              ],
              "package_integrity": [
                {
                  "hashes": {
                    "sha1": "c3dc537969fc56745a73204da81b3063b562f534",
                    "sha512_sri": "sha512-UOG7X/AW829XHcu1iR2ujidCrJFuSn2H6W5NKsxDc7piQHSUtGdWMU6ErpMecnY3Mb1PLzrL76VlRfi8huDVLQ=="
                  },
                  "filename": "web-components-9.9.10.tgz"
                }
              ]
            }
          }
        }
      ],
      "modified": "2026-10-12T14:00:05.792012327Z",
      "provider": "osv",
      "references": [
        "https://www.npmjs.com/package/@user-services/web-components/v/9.9.10",
        "https://github.com/advisories/GHSA-f3g4-6hpx-9mcq"
      ],
      "provider_metadata": {
        "malicious-packages-origins": [
          {
            "id": "IN-MAL-2026-020286",
            "sha256": "02523ee1cb3bbb9119054ec3ed14ffc62d0d33ae3bd44dc29312c772cdba106b",
            "source": "amazon-inspector",
            "versions": [
              "9.9.10"
            ],
            "import_time": "2026-09-22T14:19:07.710077681Z",
            "modified_time": "2026-09-22T13:57:51Z"
          },
          {
            "id": "GHSA-f3g4-6hpx-9mcq",
            "ranges": [
              {
                "type": "SEMVER",
                "events": [
                  {
                    "introduced": "0"
                  }
                ]
              }
            ],
            "sha256": "a26643867a117b96b0d18cd07cbec2dbc5968abf2ea90f77d2999de7806a4721",
            "source": "ghsa-malware",
            "import_time": "2026-10-12T13:47:27.084674847Z",
            "modified_time": "2026-10-12T12:55:17Z"
          }
        ]
      }
    },
    "related_cves": [],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 299932,
  "published_at": "2026-09-22T13:57:51+00:00"
}