URL Request http to find with reward (with firebug)

Hello, Every time a person is connecting for the first time in any page of our website, a popup is lunched (for russian spam website often). To be able to see the popup you need to connect from a different IP with no cookies each time. My concern is to find which script / ads network I use is running this compain. If you find the primary URL / JS that run this URL in our web pages the reward is 10$. Just send me a pm once found. the website is : [login to view URL]