Wow security help i need help bad please answer.?

i have had world of warcraft for about a year now and have high level toons and good items i was hacked a month after i started and lost everything bliz got it back and i merged with battle.net now yesterday same thing happened again my pword was changed i dont know how they got it i have never givin my pword out to anyone i changed it to another pword and started palying again then today it says account is banned because i have breached terms because someone has used my account my security mesures taking as as follows i have avast and avg virus protection merge to battle.net i just bought bliz authenticator its coming in the mail and i use ccleaner to clean up temp files and such does anyone know any other ways to keep key loggers out and futher my account protection i want it to be so secure i can barly log in to it? thank you