Desert of Fire (1971)

A desert bandit leader robs a jeep and hauls off a lot of American money. He doesn't get much of a chance to enjoy it, however, because he and his men are soon attacked by a "phantom", who kills all his men, and his own weapons mysteriously disappear. When a beautiful young woman shows up to see if he still has the money, the phantom rapes her. Another man shows up and the three decide to head into the desert to find the "treasure" and wind up finding something the weren't expecting.