The npm package 'checkout-parameters' version 35.8.5 contains malicious code that downloads and executes a platform-specific native binary from obfuscated hosts during installation or require. The payload is saved to hidden paths on the host system, given executable permissions, and launched detached, enabling arbitrary code execution. The package uses evasion techniques such as runtime hostname reconstruction and obfuscated code to avoid detection. A sibling module mimics an analytics SDK but performs similar malicious actions. This results in arbitrary attacker-controlled code execution on the installer's machine.