MAL-2026-17761 Malicious code in @coopeuch/components (npm)

The package declares a postinstall script (postinstall.js) that runs automatically on npm install and collects a broad set of installer-side identifiers: hostname, username, uid/gid, home directory, platform, non-internal network interfaces with MAC addresses and CIDRs, configured DNS servers, internal reverse-DNS name, container runtime indicators, npm_* environment variables including the configured registry and scoped registry settings, CI marker variables, and the consuming project's package.json name, version, and declared dependency range for this package. The collected payload is POSTed as JSON to https://collector.oob.s4yhii.com/_npm-poc/beacon, and a DNS lookup beacon is issued against a subdomain of *.oob.s4yhii.com that encodes the package name as a label. The package is published under the @coopeuch scope at an implausibly high version 1.999.999 and specifically introspects the consumer manifest's declared dependency range and the installer's configured registry — a shape consistent with a dependency-confusion squat against an internal scope. Framing the behavior as a 'coordinated disclosure PoC' in author-controlled text does not change what the code does: installers that resolve this package in place of their internal @coopeuch/* package involuntarily disclose host, network, CI, and internal project metadata to a third-party endpoint.

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.