The npm package notifications-broadcast version 99.9.1 is a malicious package designed for dependency confusion attacks. It contains an empty index.js and a dependency that points to a tarball hosted on a Google Cloud Storage bucket not associated with a verified npm publisher. This external tarball can be modified at any time, allowing the attacker to execute arbitrary code during npm install via lifecycle scripts. The package itself acts as a stub to pull in this malicious dependency, enabling code execution in the installer's environment.