I use Chrome. Could be just one rogue ad, hopefully.Which browser are you using? Some people report that switching to Chrome or Firefox can help. Other people use an ad blocker -- even a free version can help. Others turn off Java. See what works for you.
I use Chrome. I have also been getting the annoying video on the bottom left part of the screen, too.
On my laptop, using Windows 10, Chrome with Ad Blocker Plus = I'm getting no pop ups or ads at all.Oh gawd...I hate these pop-ads.
I have Ad-Blocker Plus, too.