Ask HN: What is this FHScan thing?

My website got a few requests from "94.242.163.1xx Mozilla/5.0 (FHScan Core 1.1) and asked for a bunch of things that (luckily) don't exist in my system, including a GET http://www.fbi.gov/ request. That's weird. I googled it. It seemed to be some sort of HTTP scanner/attacker.

I don't know what they were trying to do.

How do you guy make sure your website is safe?