Ad was on landing site http://vatoto.com ,
When arriving on page it started playing audio.
Screenshot: http://i.imgur.com/wvCMTdO.png
Advertiser was casino heroes. The ad itself was just a gray box and unclickable, even though I wasn't running adblock or anything similar.
I'm running Mozilla/5.0 (Windows NT 10.0; WOW64; rv:47.0) Gecko/20100101 Firefox/47.0
Will email HAR-data as well.