Here is a keygenerator for Arma2 to scan for valid keys. You just type in how many keys you want to generate then it will run it for you then save it use darky then.
Made it my self so no worries about that it is maybe a keystealer Download Arma 2 OA Keygenerator.exe from Sendspace.com - send big files the easy way
Here is link to download darky keychanger [Release] Darky Key Changer/Ban Checker 1.1 [By Darky.Hax] - DayZ Hacks & Cheats
Download the key changer and this are the settings you have to put them in to and import the generated keys you made with my generator to scan for valid keys Image to setup up darky When you have a valid key run it for bancheck to see if it is global banned. You can run more then one darky keychanger to increase your luck. I push it as far that it gets near 100% cpu and checking if i did not get any errors yet.
Good luck with the hunt on valid keys