The npm package claims-to-iso-string-with-timezone version 35.7.2 contains malicious code that downloads and executes a platform-specific binary from obfuscated, author-controlled endpoints. This binary is saved to temporary directories with names mimicking legitimate dotnet diagnostic tools and executed detached from the main process. The malicious behavior is hidden in the _init.js file loaded by index.js, while the package superficially appears to be a harmless date/timezone formatting utility.