Annoying Pop-Up just started

Hello! I just started recieving a pop-up asking me to open a text edit attachment of zero bytes. I did a full scan including an Ad bot scan and it is still happening. I keep hitting cancel and they keep popping up. Does anyone know what it is or how to get rid of it? My only other recourse is to delete Firefox and only use Chrome. If thats the only way to get rid of this i will start migrating bookmarks, etc.

it does seem to only come up on certain sites (yahoo mail is the one i ntice the most, but also gmail). I haven't fully tested Chrome yet either.

Any help is greatly appreciated.