Malicious code in babel-polyfill-plugin-corejs2 (npm)

{
  "id": "91cde8d3b885627238d164ca088e6904139c06c5d0808cb8b0290b44a3b01482",
  "url": "https://osv.dev/vulnerability/MAL-2026-14426",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Malicious code in babel-polyfill-plugin-corejs2 (npm)",
    "summary": "--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (13878d994b01607c379e26646449b7cca95099f9b2eb5be2e1f8e19aeea32eb3) The package advertises itself as a Babel core-js 2 polyfill plugin, but the shipped lib/index.js contains unrelated web3-core-subscriptions boilerplate followed by a Function() invocation whose body is ~110KB of obfuscated JavaScript (random identifiers, numeric offset arrays, TEA-like mixing routine, unicode-escape string literals). The Function() call executes whenever a consumer require()s the package, running the opaque payload at import time. The declared purpose does not match the shipped code, and the obfuscation is confined to the appended payload rather than being a general minification artifact. ## Source: ghsa-malware (69ae525ab6e1ea4ee1d3d1cbb451a97e4e89072feb3df4c506f51eb14a34dd66) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.",
    "evidence": "osv:MAL-2026-14426",
    "products": [
      {
        "name": {
          "value": "babel-polyfill-plugin-corejs2",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.0.1",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "MAL-2026-14426",
      "aliases": [
        "GHSA-9g6r-83hw-6cq2",
        "MAL-2026-14426"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "babel-polyfill-plugin-corejs2",
            "purl": "pkg:npm/babel-polyfill-plugin-corejs2",
            "ecosystem": "npm"
          },
          "versions": [
            "1.0.1"
          ],
          "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/babel-polyfill-plugin-corejs2/MAL-2026-14426.json",
            "indicators": {
              "evidence_files": [
                {
                  "path": "lib/index.js",
                  "tlsh": "f3b3bac722fa961dcc92cea08df45e4d43a85422cfc510c4bf9b9d5ee6ae690e7e1344",
                  "sha256": "e128537a49012ee255e98827ece385ecabeb4827ba8ce8dc2eaca045102666dc"
                },
                {
                  "path": "package.json",
                  "tlsh": "1c018920c4785eb316e923a9fc9845035270464b4c6dbc0837ac52ac8f5d5de98fc6ad",
                  "sha256": "0a2baad786bbd1b0fd113b5900f912aaa621a10f127b16c67beb4c2424e9eeba"
                }
              ],
              "package_integrity": [
                {
                  "hashes": {
                    "sha1": "076c925c9d1cf6a577096db7b79ab1ef3879459c",
                    "sha512_sri": "sha512-mzX1+c9z0ZZLO4As7ARbnPLaXslwBKS3y90lV/SOAPKhaBpr1L38ZQzBxEZTQWmjVM7kmqpek4BBq4N1n15Mhw=="
                  },
                  "filename": "babel-polyfill-plugin-corejs2-1.0.1.tgz"
                }
              ]
            }
          }
        }
      ],
      "modified": "2026-10-14T22:30:05.253335401Z",
      "provider": "osv",
      "references": [
        "https://www.npmjs.com/package/babel-polyfill-plugin-corejs2/v/1.0.1",
        "https://github.com/advisories/GHSA-9g6r-83hw-6cq2"
      ],
      "provider_metadata": {
        "malicious-packages-origins": [
          {
            "id": "IN-MAL-2026-018647",
            "sha256": "13878d994b01607c379e26646449b7cca95099f9b2eb5be2e1f8e19aeea32eb3",
            "source": "amazon-inspector",
            "versions": [
              "1.0.1"
            ],
            "import_time": "2026-08-24T16:49:14.751664125Z",
            "modified_time": "2026-08-24T16:45:38Z"
          },
          {
            "id": "GHSA-9g6r-83hw-6cq2",
            "ranges": [
              {
                "type": "SEMVER",
                "events": [
                  {
                    "introduced": "0"
                  }
                ]
              }
            ],
            "sha256": "69ae525ab6e1ea4ee1d3d1cbb451a97e4e89072feb3df4c506f51eb14a34dd66",
            "source": "ghsa-malware",
            "import_time": "2026-10-14T22:23:09.401333799Z",
            "modified_time": "2026-10-14T22:21:14Z"
          }
        ]
      }
    },
    "related_cves": [],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 317603,
  "published_at": "2026-08-24T16:45:38+00:00"
}