Malicious code in css-field-sizing-polyfill (npm)
Historical advisory saved 24 Oct 2026 13:17:17 UTC. The publisher may have updated it since then. Latest advisory.
osv · MAL-2026-17478
Published--- _-= Per source details. Do not edit below this line.=-_ ## 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.
- Source published
- 4 Oct 2026 23:14:01 UTC
- Source modified
- 4 Oct 2026 23:30:06 UTC
- Saved here
- 24 Oct 2026 13:17:17 UTC
- Source terms
- OSV · upstream source license applies
Original source record · Cite this exact observation · Complete original publisher JSON
Source: osv · OSV · upstream source license applies. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.