I just gave it a quick try. It's portable, so nothing gets installed. It's very slow at scanning. While it does seem to do fairly well at detecting PUPs, the heuristics causes many false positives. There is a thread started by the author, at Malwaretips. https://malwaretips.com/threads/x-sec-antivirus.61121/
Lately they moved to managed C++ (.NET) for the sake of creating a better GUI, which a route I really didn't like instead of just sticking with unmanaged C++ turns out that GUI isn't something that deserved the efforts by just being so untidy and very traditional. But still, I appreciate the work so far since I (think) it was made by an individual.
