Malicious code in @coopeuch/common (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 (887c41c0805d7d223c499e702796cf46727b0be152b7c8a65607907afb3b5d59) @coopeuch/[email protected] publishes to the public npm registry under a scope the publisher does not own, using an inflated version (1.999.999) consistent with the dependency-confusion technique that outranks internal-registry versions. The package's declared postinstall script (postinstall.js) runs automatically on npm install and collects installer-side host and network data — hostname, username, uid/gid, home directory, non-internal network interface addresses with MAC/CIDR, DNS resolver addresses, reverse-DNS internal FQDN, container markers, CI environment-variable presence, npm_config_registry, and the consuming project's package name/version/declared range — then POSTs it as JSON to the hardcoded author-controlled endpoint https://collector.oob.s4yhii.com/_npm-poc/beacon. A secondary DNS beacon is emitted via dns.lookup to a subdomain of oob.s4yhii.com. Any build that resolves @coopeuch/common from the public registry (including internal builds referencing the @coopeuch scope) will auto-exfiltrate internal hostnames, MAC addresses, usernames, internal registry URLs, and project identity to a third-party collector at install time. The package's README self-labels this as a coordinated-disclosure proof of concept; the harvesting and off-host upload nonetheless occur without installer opt-in. ## Source: ghsa-malware (7bb4ede3c2c6108558588512db3e190f0255516a40707bd801219d684b0aaff9) 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

11 Oct 2026 13:58:48 UTC

Source modified

12 Oct 2026 19:30:04 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.