Using Firefox, links appear all over any website or page I view in places they should not. For example, if I typed that last sentence and posted it on a forum, the word "appear" would turn into a link. When I hover the mouse over it it shows an add for various things, without clicking on it. Does anyone know how to get rid of this?
Are they double-underlined? There are many add-ons that contain code to do this, some of which get installed by accident and others of which you might have installed not realizing how they behaved (e.g., VideoFileDownload).
I suggest going to the following tab and disabling ALL non-essential extensions, then restart Firefox and see whether the problem is resolved. You also could remove all the ones you do not recognize or do not really need.
orange Firefox button or classic Tools menu > Add-ons > Extensions category