The npm package 'checkout-use-boolean' version 35.4.5 contains malicious code that executes upon module import. It loads a secondary script that downloads a platform-specific binary from obfuscated worker domains, using DNS TXT record fallback channels to evade detection. The payload is saved to temporary directories with disguised filenames, made executable, and launched detached via system shell commands. This behavior triggers automatically when the package is required by any other module.