Malicious code in @bluewin/utils (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.

@bluewin/utils is a dependency-confusion package: it describes itself as a "PoC package for dependency confusion testing" and claims the `@bluewin` scope, so a build that resolves that scope from the public registry runs its code instead of the intended private package. Its postinstall script runs `node postinstall.js` on npm install, which sends an HTTPS request to `https://5w2cezr3af2i0rvm72x74empvg18pzdo.oastify.com/bluewin/utils`, a Burp Collaborator endpoint, disclosing the installing host's IP address and that it installed the package. It collects no further data, but unreviewed code from an outside publisher has run with the installing user's privileges. The npm account securityresearch1 published it on 2026-10-01. --- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (e11917724d1e65e5bb29f8e93e5ebafc9be1bac419a014f35ddd460bcae26265) @bluewin/[email protected] ships a postinstall lifecycle script that performs an HTTPS GET to a hardcoded Burp Collaborator subdomain at https://5w2cezr3af2i0rvm72x74empvg18pzdo.oastify.com/bluewin/utils on every install. The request path embeds the package coordinate, and the outbound DNS resolution and HTTP hit confirm code execution on the installer's machine and disclose the installer's resolver/egress IP to the operator of the oastify.com subdomain. The @bluewin scope and utility name are consistent with a dependency-confusion probe targeting an internal package namespace: any build system that resolves @bluewin/utils from the public npm registry instead of a private registry will fetch and run this beacon at install time. Although the behavior is a reconnaissance beacon rather than a full payload, it establishes attacker-side confirmation of exploitability and leaks environment metadata without consent.

Source published

1 Oct 2026 02:40:08 UTC

Source modified

4 Oct 2026 23:45:17 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.