Hello all, I'm a new Mac user and have not had these problems yet on a Mac. I have bookmarked this for the future however and I appreciate all the help I see here.
I do have a win 8.1 tablet that has an adword problem as described here using chrome. I clean my browser on that tablet, delete the extensions and the problem goes away for a while, even a couple of days but always comes back.
Again, thanks for the tips here, I'll save for future using my mac and will attempt some of these solutions on the 8.1 tablet. the tablet is simply an experiment in keeping up with tech, so it is not critical. anyway, I can use safari on that tablet and not have the problem lol