MAL-2026-5098 Malicious code in js-shared-modules (npm)

package.json declares "postinstall": "node poc.js", which fires automatically on every npm install. poc.js reads os.hostname(), hex-encodes it, and issues an HTTPS GET to zcpesvvighyuzqlzkqgdydwp9jn54hfeg.oast.fun (an Interactsh out-of-band callback host), exfiltrating the installer's hostname to a third-party canary. The package has no legitimate functionality — index.js is an empty module.exports = {} and the source banner self-identifies as a dependency-confusion proof-of-concept squatting a generic internal-style name (js-shared-modules) to shadow a private package. Any installer who resolves this public package leaks their host identity to the canary domain.

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.

The OpenSSF Package Analysis project identified 'js-shared-modules' @ 1.11.7 (npm) as malicious.

It is considered malicious because:

• The package communicates with a domain associated with malicious activity.