Simple scanning question

Hi all, I thought this would be the most appropriate place for this question. After enjoying WoW on a Mac for awhile, then not enjoying it so much when the patch came out, I've decided to start playing wow on my laptop. I have an authenticator, but I still want to do regular scans using Malwarebytes to keep my system clean. So far, for the last two months or so, everything has been clorox clean.

Now this might be a dumb question, but when doing the scans with WoW open and random letters typed in the password fields, is WoW supposed to be the active program? or does it need to be in the background? Does it matter either way? Yeah, total noob question but I'm used to Mac's. Knowing so many people that have been compromised, including a friend with an authenticator that downloaded a program posing as wowmatrix, I don't want to be too careful.