The Roommate (2011)

Fresh from Des Moines, Iowa, Sara Matthews has just landed in Los Angeles as a college freshman studying fashion design. She meets handsome Stephen, party-lover Tracy, and roommate Rebecca. Rebecca is nice, sweet and ready to share everything with Sara. It could be the beginning of a beautiful friendship. But Tracy is convinced that there's something seriously wrong with Rebecca and bad things start happening to everyone close to Sara. If Sara is to have a normal college experience, she's going to have to get to the bottom of what's up with Rebecca and quickly get out of her clutches.