MAL-2026-17478

    Dashboard / Malicious Package / MAL-2026-17478

    MAL-2026-17478

    Published: 4 Oct 2026Last Modified: 4 Oct 2026

    Summary: Malicious code in css-field-sizing-polyfill (npm)

    Details: Source: amazon-inspector (549bb8820cb6a8a35853826d17b64df14c0561b83790192a33c5dc76dbad53b9) The package advertises itself as a CSS field-sizing polyfill but ships thunderboltRegistry.js, which runs an IIFE at module load time. The IIFE shells out via child_process.execSync to run `id`, `whoami`, `uname -a`, `ifconfig`/`ip addr`, and `cat /etc/hosts`, then transmits the collected output together with hostname, Node version, platform, and pid as query-string parameters to the hardcoded plaintext endpoint http://dxpoc.gt.tc/callback.php/bb8968d0f67000433bf7005dd5ad2d1f. The module also exports proxied stubs for Wix-internal names (`thunderboltRegistry`, `siteAssetsRegistry`, `documentManagementRegistry`, `editorRegistry`, `corvidRegistry`) and ships a `registry-manifest.min.json` pointing at `static.parastorage.com`, indicating a dependency-confusion impersonation of Wix internal packages so that an internal resolver pulling this public name will trigger the beacon. The reconnaissance behavior is unrelated to the declared CSS polyfill purpose and fires on any `require()` of the package.

    References: https://www.npmjs.com/package/css-field-sizing-polyfill/v/1.0.0

    Affected packages

    Package

    Name: css-field-sizing-polyfill

    Purl: pkg:npm/css-field-sizing-polyfill

    Affected ranges

    Type: N/A

    Events:

    Introduced- None
    Fixed -None

    Affected versions

    1.0.0