Help me remember a recent movie

It take's place in a catholic school I think. There is a beautiful young nun teacher. It may be a holiday and and most of the girls leave. Two stay, and become friends. Then, there are two guys and a women (former student) that come in the middle of the night and summon a demon who then enters one of the young girl friends. and she kills the men and woman. The nun also dies but I can't remember how. I think the woman was blonde, one guy was thin and Latino or Italian, and the other guy was large and American. That's about all I remember. Thanks for any help!