Network is part of an alien race that can shapeshift and has no real shape of their own. He was onboard a war vessel that was attacked and heavily damaged so were thrown off course. The escape pods were eventually jettisoned by the pilot before he died and one travelled for years until it impacted Earth .
A branch of the military/government found the pod and set to work examining it. When they eventually managed to open it one of the engineers came into contact with what was inside and collapsed. What stepped out had taken the form of the engineer and managed to escape. For some reason he cant remember anything about what he is and where he is from. He spent the first years hiding and trying to survive. Some of the memories from the Engineer had been passed onto him so he had a vague understanding of how things work. When he realised he had the ability to change his form he thought he was just a power.
With his unique abilities he is an ideal infiltrator and used his powers to gain access to classified information and technology and sold it on to the highest bidder. No one knows what abilities he has or how he gets the information, all they know is he can get the job done.