I watched this movie more than 21 years ago. It is about a group of friends all men and only 1 woman who received an invitation and they are taken to some kind of jungle. It is a tramp, they were invited by a guy that thinks he was betrayed by them and try to kill them all. He was in love with the woman and at the end I think she is the only one who survives. I am not sure if all them were in the army, and if it was a real jungle or just a recreation made by the killer.