There is a blattant virus activity going on my computer ( porn sites poping up left and right ) and a fake antivirus that I have never installed and hear of before called "Antivirus software" telling me that my computer is infected and to "Buy Now" to remove the viruses.
After a full scan of my system with MacAfee Security Center, it says that there 's nothing to report! Everything is fine!
I have no idea of how I got this virus in the first place. I have 3 separate accounts on my system: Admin, Me, and Guest. I use the "Me" account for my day to day work and only used "Admin" briefly to install only trusted software. I haven't installed anything new in a long while.
Since MacAfee can't get rid of it, what else is left to do? reformat?
This sounds very much like Antivirus System Pro. Even if it goes by a different name, the techniques for getting rid of it are pretty much the same as the ones in this link to bleepingcomputer
Follow the instructions in the article and this rogue program should be successfully removed. If the removal fails, get a screenshot of the fake AV program and include it in your next post. We may have to move to a more targeted approach - McAfee has some specialised tools available.