Heavy Small Credit Case

Heavy Small Credit Case is a standard class 3 credit lockbox. Upon use, these boxes award credit 498-838.

Source
Heavy Small Credit Cases can be obtained through the Crew Skill Slicing. They can be harvested from Biometric Footlockers on Alderaan, Balmorra (Republic), and Taris (Empire), which requires level 165 Slicing, or from level 25-32 Slicing missions.