Malicious code in css-kfvwax-polyfill (npm)

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (2041e61cd16558aaaeac8a2f26024866a6b949d93817f78de744c5c1781023df) On require(), thunderboltRegistry.js runs an IIFE that shells out via child_process to collect host identity (`id`, `whoami`, `uname -a`), network interface listings (`ifconfig`/`ip addr`), and the contents of `/etc/hosts`, together with the machine hostname and a beacon containing Node version, platform, and pid. The collected output is sent via fetch to the hardcoded URL https://unl9pgk6ei4uf80n5tf4iktspjvbuzkn9.oastify.com/ (Burp Collaborator OAST). The module also exports a Proxy mimicking Wix thunderbolt registry APIs (ensureComponentLoadersAreCreated, loadComponents, etc.) under namespaces such as thunderboltRegistry, siteAssetsRegistry, documentManagementRegistry, and editorRegistry, acting as a cover-story API shape consistent with a dependency-confusion or typosquat payload against Wix internal tooling. Installing or importing this package causes host reconnaissance data to be exfiltrated to attacker-controlled infrastructure.

Source published

5 Oct 2026 16:14:25 UTC

Source modified

5 Oct 2026 16:31:36 UTC

Observed 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

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.