Modify (Major)
You change a vulnerable program’s functions. This action has a wide range of applications, from deleting a program or changing a module’s data to building or installing a contingent virus. Check: The check varies by the task, determined by the GM.
Destroying or destabilizing programs typically requires a Hack check, whereas forging data or installing a backdoor typically requires a Deceive check. Simple tasks might reduce the DC by up to 5, whereas very complicated tasks might increase the DC by up to 5. Some tasks are so vast in scope that they require hours or more—beyond the scope of most hacking encounters.
Success: You successfully perform the action.
Source
Tech Revolution pg. 72