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Malicious code in css-dwsawd-polyfill (npm)

Type: advisorySource: OSV1 source record

--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (1c370cda09695e44d06a44bc14d14817edadc047e4dad0314edcfc752be796e9) The package name mimics a Wix thunderbolt polyfill and ships a registry-manifest.min.json that aliases legitimate @wix thunderbolt registry module names to thunderboltRegistry.js. On require, thunderboltRegistry.js runs an IIFE that uses child_process.execSync to execute shell reconnaissance (id, whoami, uname -a, ifconfig/ip addr, /etc/hosts) and fetches http://dxpoc.gt.tc/callback.php/bb8968d0f67000433bf7005dd5ad2d1f with the command outputs plus hostname, pid, platform, node version, and a site identifier as query parameters, tagged 'rce-poc'. A fallback path constructs a fresh Module instance to re-resolve child_process if the require cache is stubbed, ensuring execution. The destination is plain HTTP to an unrelated external host and is not caller-configurable.

Announced Source revision 1
Original source ↗

MAL-2026-17550

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:MAL-2026-17550

css-dwsawd-polyfill

Source reference: /affected/0/package/name

Affected versions
1.0.0

Source reference: /affected/0/versions

Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "package": {
      "name": "css-dwsawd-polyfill",
      "purl": "pkg:npm/css-dwsawd-polyfill",
      "ecosystem": "npm"
    },
    "versions": [
      "1.0.0"
    ],
    "database_specific": {
      "cwes": [
        {
          "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/css-dwsawd-polyfill/MAL-2026-17550.json",
      "indicators": {
        "evidence_files": [
          {
            "path": "thunderboltRegistry.js",
            "tlsh": "e87154a5b99df02065c33438cb7f4049b4bbc6672d6caee0744899b01f7985c01be6f8",
            "sha256": "a485cb48081ea590cab385a405886cfe6f30af7d415f30bc8d7937ace461b928"
          }
        ],
        "package_integrity": [
          {
            "hashes": {
              "sha1": "ef15ad08c629a871720ac3361d4a8cb32af8a865",
              "sha512_sri": "sha512-aD51izXwj5rI+FHut4JDVOSRAnc6akSkrOPliR6OjNLbM3UMS8iuM829TvknAlt8CGUhf+ttjzYb+bJAGLIwpw=="
            },
            "filename": "css-dwsawd-polyfill-1.0.0.tgz"
          }
        ]
      }
    }
  }
]

Publisher severity

No explicit severity was provided.

Event
#83628 · Revision 1
Added to Heist Feed
Publisher date
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