Captain: Donald Varley
The USS Yamato was a Galaxy-class Federation starship constructed in the late 24th century and one of the first of its class. During a patrol mission along the Romulan Neutral Zone, the ship discovered ruins from the Iconian civilization on a planet in the Neutral Zone and entered the zone to investigate them. The ship encountered a probe that transferred Iconian software to the ship's computer. The Iconian code began spreading through the ship's computer system like a virus, causing various systems to fail as it damaged their controlling software.
The Yamato left the Neutral Zone to communicate its findings to Starfleet and managed to contact the USS Enterprise. Shortly after making contact with the Enterprise, the virus damaged the control software for the ship's warp core, resulting in a warp core breach that completely destroyed the ship.