Looking to buy, I added you on discord.
So it IS in fact legit, If its your first time using a script executor on arma (like me) it can be pretty confusing, But luckily M5 is very nice and shows you/tells you how to do everything from start to finish. To use this executor and not get banned from servers for doing something stupid it does require some IQ in the brain and knowing what will and wont get you banned, So with that being said I myself have fucked up and gotten banned for trying to spawn stuff in or using no recoil/sway. So the executor itself is undetected but how YOU use it depends on your detection rate.
TL;DR: Legit program, Nice guy/Seller but it requires some brains to use.