Okay, this looks like something my friends and I would have done in highschool. I originally got the link from CTodd, but ended up revisiting to watch it over and over. The song is very catchy. When I googled it, I found out that the song is and apparently has been popular on the internet long enough to have spawned multiple remakes, some of them quite frightening.
I found out that the song is actually a Romanian song called Dragostea Din Tei. Here are the lyrics and translation, and here is the original music video, which is nearly as frightening as that last remake.