Scans your WordPress installation for security vulnerabilities.
The weird thing is that they created two plugins: Acunetix WP Security, and Actunetix Secure WordPress (yes, like the "Judeans People Front" and the People's Front of Judea, from Brian's Life).
And also it not consistent: in one options page it recommends me to change 644 permissions from settings.php to a lower value, while in other page, it changes that settings to 644 to the same file. And it says that you have a lot of problems, but doesn't fix most of them automatically. So it's confusing, and complex to understand and use. Previous versions were much better :(