Why is Yahoo hijacking my (Firefox & Chrome, though I mainly use Firefox) browser and how do I ban them from taking over my default search? I set my browser up THE WAY I WANT IT and it pisses me off that Yahoo constantly changes my stuff. I've done countless searches about how to fix this and going back many years people seem to have a similar issue.
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.