Years ago, I used DBTech's vBSecurity for vBulletin and was sold on their commitment to make forums safer from hackers.
Fast Forward until now and I was so pleased to learn that they were going to make a similar (but even better) add-on for the XenForo Forum software.
As soon as it came out of Beta, I purchased a Lifetime License and installed it immediately. This newer version has so many bells-n-whistles, it's hard to count all the ways your forum is protected.
Their communications are excellent and they are open to questions and/or feedback about ways to improve the add-on even further.
If you're looking to improve the security of your forum you've worked so hard to create, I know of no other add-on as capable as this one for doing so. HIGHLY RECOMMENDED