I've tried all of these to no avail: https://support.mozilla.org/en-US/questions/952305
Is it possible to have my browser (AND YAHOO) respect my wishes and stop hijacking my browser?
Edit: I don't even use Yahoo for anything, nor ever visit their website, so it shouldn't be some sort of random leeching software that they attached while visiting their site, which is the most baffling aspect about this.