Frustrating

I just spent the past two hours trying to rid my Microsoft Word of a virus. Macs are not supposed to get viruses!! I finally found some free antivirus software that will repair my infected files. I don't think it gets rid of the virus all together, but maybe it will slow it down. My googling research tells me that it should stop after July 31. It's some weird thing that attacks your macros between July 23-31. Who comes up with these things??!!