Pup

Pup was the name given to an alien computer program by the crew of Deep Space 9 in 2369. It came to the space station from the Gamma Quadrant in a probe.

After the crew scanned the probe, "Pup" was downloaded into the station's computer, causing widespread throughout DS9. Miles O'Brien compared it to a puppy that needed attention and created a "doghouse" for it in a file in the computer, which also included the station's backup files to keep Pup occupied. 

Several months later, the crew brought Pup out of the "doghouse" to distract the Tschak entity Enak, which had taken control of the station.