They are not really hackers. Most of them are just script kiddies who pay for cheats made by someone else. They buy access because they cannot play the game properly without cheating.
BattlEye needs to improve a lot when it comes to detecting cheats in DayZ. The cheat developers are making huge amounts of money selling these programs and subscriptions, so they are constantly updating them to avoid detection.
A lot of modern cheats are also harder to detect because they can interact with game memory and use different methods to hide what they are doing. That is why DayZ developers need to work much more closely with BattlEye and come up with better ways of detecting cheating, instead of only relying on finding known cheat programs.
They should also be looking at player behaviour and server-side information. Things like impossible aim, tracking players through walls, knowing where players are when they should not, strange bullet behaviour, impossible reactions and other abnormal gameplay should all be used as part of the detection system.
Bohemia Interactive should also seriously look at taking legal action against the people creating and selling these cheats. These cheat sellers are making money from damaging the game, ruining servers and affecting legitimate players. Other game companies have taken legal action against cheat developers before, so it should at least be something Bohemia considers.
At the moment it feels like the cheat developers are always one step ahead. DayZ and BattlEye need better detection, better server-side monitoring, faster bans and stronger action against the people actually creating and selling the cheats.