Sweatshop (2009)

Charlie and her friends break into an abandoned warehouse and begin setting up an impromptu party. Unbeknownst to them, something lurks in this dark place... a presence so horrific, so monstrous, it has no name. Fueled by uncontrollable, unprovoked rage, this Beast knows only one thing - Charlie and her companions chose the wrong building, and they're about to pay for it.