MAL-2026-16309 Malicious code in npmscript_tesstalert_unpkg (npm)

The package ships a single script exposed via the unpkg field for CDN loading into web pages. When executed in a browser, the script reads document.cookie and assigns window.location.href to https://webhook.site/4c14c8e4-721e-471d-807c-1a2aa216512a/ concatenated with the cookie value, causing the browser to navigate to that attacker-controlled endpoint carrying the victim's cookies. The identifiers location, href, and cookie are assembled from split fragments ("loca"+"tion", "hr"+"ef", "coo"+"kie") to hide the sensitive property accesses from string-based scanners. Any page that loads this file via unpkg or bundles it exfiltrates its cookies to the hardcoded webhook.site collector.

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.