Neither, the statcounter.com and googlesyndication.com scripts are the problem.
However I have stumbled around in there and not got a single alert. I tried to go to the thumbnails.php link you gave only to get an error, The selected album/file does not exist !
So I had to do a search to return some results and then click on one of them to get the alert.
Now I have had a look at the page code where the alert happens and I can only see one script tag which might possibly be causing this alert and it is one of the google scripts at the end of the page.
But, I'm not convinced it is a good detection, so I have submitted it for analysis.