I am currently having an issue with my Macbook Air. While running firefox I began noticing surveys popping up when I visited popular websites, I also began noticing fishing type ads at the top of these websites as well. All that the ads say is "Ads By: Media Player." It appears this is some type of spyware program/trojan? Any ideas on how to remove it on a mac? I attempted to run macscan but it was not detected. Any help would be greatly appreciated, thanks!