Security Tips: Protect your WordPress website Admin Area
It is important to restrict the access to your WordPress admin area only to people that actually need access to it. If your site does not support registration or front-end content creation, your visitors should not be able to access your /wp-admin/ folder or the wp-login.php file. The best you can do is to get our home IP address (you can use a site like yoursite.com for that) and add these lines to the .htaccess file in your WordPress admin folder replacing xx.xxx.xxx.xxx with your IP address.
Allow from xx.xxx.xxx.xxx