it's most likely a scam-virus, if you look at the ads there should be a statement on the bottom-right of the ad saying "ads by [...]" if you look for that in your Control Panel -> Uninstall software thingie you should be able to find it
if not just run a virus scan with Malwarebytes and restart your computer
if that doesn't work too just install Adblock
avast and adblock plus, hate to take ad revenue from admin, but i dont feel like letting my only means of contact with the outside world get fried by some **** that i could easilt prevent.