I have been interrupted multiple times by a cover screen that is a mimic of one of the Firefox update pages, which says it is urgent that I download an update. I did so the first time, then didn't open it and deleted it from Recycle Bin as well, when it occurred to me you don't use that alarmist language. It comes up about once in 3-4 times on the computer. The latest, I noticed, was when I was using Comcast's email and doing a search. I started to copy down the website address but it was long and I thought I managed a screenshot, but it didn't take, so this address is incomplete: dokeeandroidkothon.net/2530095008050/e644f71bbdb9bea462db5887.... I use the highest levels of Malwarebytes and Norton, and this only occurs in Firefox and is not noticed by them until MB (after the first time) tells me it deleted the download file.. But their reporting section does not tell me about this blockage. It seems to be internal to Firefox - why is it still happening? is it happening to no-one else?