Bots and web crawlers coming to your site check the content of the Full user agent string and block the ones other than the white list. In addition, you can manually blacklist the ip address, if you activate the automatic ip blocking option, it will block the ip address that makes more than 5 requests within 1 minute for 4 hours.
Этот плагин можно скачать и использовать при автономной установке WordPress.