Malicious code in web-vitals-polyfill-core-v1 (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 (38311c0f483e9485a7b5e8aa7f9a093a40203d8e1a025c0bf5850c2874cffdfa) The package name mimics the widely-used web-vitals polyfill but the tarball ships disk/index.min.js, a base64-wrapped service-worker payload (self.__PWA_ROUTER__.executeTacticalRouting) that resolves an active destination via DoH TXT lookups of api.chinazhangsan.ccwu.cc (queried through doh.pub and dns.alidns.com) with base64-encoded fallback endpoints on gist.githubusercontent.com/chinazhangsan999-crypto and api.npoint.io, performs decoy fetches, and issues Response.redirect(targetUrl, 302) to the resolved host. package.json declares main: index.js which is not present in the tarball, so the package has no legitimate library surface; its shipped code is exclusively the obfuscated redirector, intended to be loaded into a consuming site's service worker where it can hijack end-user navigation to attacker-chosen destinations resolved at runtime through multi-provider DNS-over-HTTPS and paste-site fallbacks. ## Source: ghsa-malware (583291fe7133304271006d1ca425c04aebce7279be07963310434403dfc19319) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

Source published

30 Sep 2026 00:39:47 UTC

Source modified

30 Sep 2026 07:00:32 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.