Can't remember which movie?

their was a movie not so long ago about a college girl that was hired by a nice family to babysit their 4 year old son. everything is fine until a crazy killer smashes through the door. she tries to run away but remembers the kid and goes back to save him. she attacks the killer (he was a big brute, think he might have had a few scars on his face) and she kills him. looking closer she sees he has a white coller on. he is a priest. going back into the living room she finds the cowboy hat on the ground( his parents said he loved that hat as ways had it on even to bed) looks up she finds the with horns on his forehead quote the kid "hello". the parents are back the know that she has found out their secret that that the kid is the Antichrist. and so on i think thats enough to find out what the movie is called. need movie's title. think it might have been called the babysitter.