John Carpenter's Tales of Science Fiction: The Envoy

Since college, Steve Allard and Ben Raines have competed to be the first to make alien contact. Now they both apparently succeed at the same time -- but one contact is a transmission, and the other seems to be a ghost. What Steven calls "the Envoy" offers enormous benefits to humankind. But Ben's more sinister Creature warns against the Envoy's generosity. Now he must go to war against his best friend to try and stop the Earth from being ravaged.