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 Any luck? Likely related threads: * [https://support.mozilla.org/en-US/questions/940417 Wordpress site hacked but only in Firefox] * [https://support.mozilla.org/en-US/questions/927889 Text-Enhance plugin, can't get rid of it and is not in my plug-in's or extensions list. I've tried everything that I could find online to fix it. Nothing worked]

It turns out the program i downloaded to view CSV files added this problem. after uninstalling it and restarting it went away. thanks. And yes they were double underlined.