The npm package 'nottuff11' contains malicious code that facilitates mass publication of nearly 100 misleading package names by rewriting package.json and republishing. It includes a browser Service Worker that serves a heavily obfuscated web proxy frontend with a popunder redirect to an external site. The package does not auto-execute code during Node installation, so the primary harm is registry namespace abuse and browser-side malicious behavior. According to one source, any system with this package installed should be considered fully compromised, with immediate secret/key rotation recommended. Removal of the package alone may not eliminate all resulting malicious software.