Added the Wordfence Security plugin that I heard about on an episode of WPwatercooler back in December, 2013. It is a very comprehensive security plugin that covers a lot of real-time things. It works in conjunction with Acunetix Secure WordPress.
The Secure WordPress plugin removes an number of things that give hackers more information about the WordPress install than they should have. It can also provides a tool change the database prefix and scans for file permissions as well as adds index.php files to prevent users from seeing directory contents.
The Wordfence plugin allows you to scan files vs their copies of the originals to see if they have been modified and shows you how they have been modified. It checks for many backdoors and allows blocking of incoming traffic. Another feature is that you can have email notification sent for a variety of triggers. If you have the premium version you can schedule scans.