ROT: Reunion of Terror (2009)

An unofficial year high school reunion sets the stage for terror in this independent shocker. A decade after graduating, six friends come together at a remote hunting cabin to reconnect, and catch-up on lost times. Meanwhile, out in the darkness, the rotting remains of two murdered campers fester on the forest floor. Before long six becomes five, and whispers of a serial killer prompt the others to fear for their lives. But is the maniac a stranger, or someone who's been with them all along?