Malkor Trel, a Human male, was a member of the Alliance to Restore the Republic during the Galactic Civil War era.
Trel operated as a spy for the Rebel Alliance, and at some point before the Battle of Hoth which took place in 3 ABY, he managed to infiltrate the ranks of the Super Star Destroyer known as the Executor. He secured a position within the vessel's droid pool, functioning as a droid technician, and successfully gathered intelligence for the Alliance regarding the deployment strategies of the Imperial Fleet. Nevertheless, in 3 ABY, Lieutenant Tanith Sorn, one of the officers serving on the Executor's bridge, uncovered proof that Trel was a Rebel operative; in response, Trel reprogrammed a quartet of ASP-7 labor droids with the intention of murdering Sorn.
Darth Vader formed an investigative unit from the Executor's crew to look into Sorn's demise. As part of their investigation, they questioned Trel, who was considered a potential suspect. Shortly thereafter, the Class 720 freighter Onderian Raptor arrived at the Executor, with the objective of extracting Trel from the ship. However, the freighter's crew was subdued, and the vessel was seized. Trel made his way to the ship and secretly disabled the tractor beam systems located in the hangar where it was docked, with the intention of escaping the Executor. However, the team investigating Sorn's death discovered Trel's scheme and confronted him on the freighter. He confessed that his mission had forced him to kill Sorn, and he offered the team the chance to join the Rebel Alliance, inviting them to come with him.