Want to know more about anti-cheat Engine.

I am playing with my friend at Ragnaros and he got kicked from server that says Account JACKIEISFAGGIE has been banned for 10 days. Reason Sentinel Anti-Cheat. But I am pretty sure we are not using any cheating software we are just lvling at the barren. Then when we got to lvl 12 he got kicked again. I just want to know what kind of software can trigger anti cheat Engine. Please replay me if you know how to solve this problem. We just want to play WoW. Thanks a lot .