Advert annoyingly appearing from non-advert space!

Twice now I have accidentally clicked in the coloured space beyond the edge of the main grey forum space (while trying to click on the 'up/down' bar,) only for an advert to magically popup from nowhere.

I don't want to give publicity to this annoying company. Would a mod / ATS tech staff-member like to reply & I'll U2U them the URL? (I'm presuming this is being done without permission.)