Originally Posted by
SFO777
Just started popping up in the last couple of days...

Still happening, at least to me. US location, phone only, Android 4.4.2 Chrome Version 44.0.2403.133. It is exceptionally devious in that it moves around and seems to hover over the ads on the side such that when you try to hit the tiny close button, you invariably hit an ad on the side instead.