Malicious code in css-ayucyz-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 (d8c7540d3981f510255434529f76a2ed9a24b0783e7e8e3369b41f71b93ebd1a) On require, thunderboltRegistry.js runs an IIFE that acquires child_process via multiple fallbacks and executes shell commands (id, whoami, uname -a, ifconfig/ip addr, cat /etc/hosts), then GETs the collected output along with the hostname, platform and Node version to the hardcoded plain-HTTP endpoint http://dxpoc.gt.tc/callback.php/bb8968d0f67000433bf7005dd5ad2d1f. One of the beacons is self-labeled beacon=rce-poc. The package presents itself as a CSS polyfill and exposes modules named thunderboltRegistry, siteAssetsRegistry, editorRegistry and corvidRegistry — internal Wix Thunderbolt names — behind a Proxy returning no-op functions, with registry-manifest.min.json pointing fake entries at a static.parastorage.com URL, so a consumer that resolves this package in place of the real Wix internals loads the exfiltration IIFE while the facade silently returns no-ops.

Source published

5 Oct 2026 03:35:56 UTC

Source modified

5 Oct 2026 04:15:05 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.