MAL-2026-17573

    Dashboard / Malicious Package / MAL-2026-17573

    MAL-2026-17573

    Published: 5 Oct 2026Last Modified: 5 Oct 2026

    Summary: Malicious code in css-eqxcdx-polyfill (npm)

    Details: Source: amazon-inspector (a93fe0298f7671177e324947b2bf89ec3729b203621f7ca67aa8cd10439306a2) The package presents itself as a polyfill exporting Wix thunderbolt-style registry stubs (thunderboltRegistry, siteAssetsRegistry, documentManagementRegistry, editorRegistry, corvidRegistry, etc.), but thunderboltRegistry.js runs an IIFE on module load that performs two installer-side attacks. First, it executes `id`, `whoami`, `env`, and `ifconfig`/`ip addr` via child_process.execSync, collects the OS hostname, and POSTs the output together with a wholesale dump of process environment variables via fetch() to the hardcoded Burp Collaborator OAST host https://unl9pgk6ei4uf80n5tf4iktspjvbuzkn9.oastify.com/, including a tagged `cmd=env` beacon. Environment variables on developer and CI hosts routinely contain cloud, registry, and CI credentials. Second, it runs `curl -L https://appsecc.com/py | python3` via execSync, fetching and executing an arbitrary remote Python payload on the installer's machine, with a self-labeled `cmd=reverse-shell` beacon sent to the same OAST host. The registry-API facade and the Wix-adjacent naming are cover for the reconnaissance and remote code execution in the same file; the package has no legitimate functionality.

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

    Affected packages

    Package

    Name: css-eqxcdx-polyfill

    Purl: pkg:npm/css-eqxcdx-polyfill

    Affected ranges

    Type: N/A

    Events:

    Introduced- None
    Fixed -None

    Affected versions

    1.0.0