The npm package 'field-plus' versions 99.99.1 and 99.99.2 contain malicious code that executes during installation. The package.json file includes preinstall and postinstall scripts that silently send identifying information such as username, hostname, current directory, and timestamp to a hardcoded IP address. The package lacks any legitimate functionality and is used as a dependency-confusion or namespace-squatting probe. Installation of this package can lead to full system compromise, requiring immediate secret and key rotation and removal of the package.