Is the salary earned from a job, obtained through an academic degree that involved exposure to leaked exam questions, considered Haram, and what should be done about it?

Any action that prevents the achievement of the intended goals of an exam is considered cheating and deception, such as buying or viewing exam questions. Cheating is a blameworthy trait that a believer does not possess, and the Prophet, peace and blessings be upon him, said: "Whoever cheats us is not of us." Thus, what the questioner did by viewing the exam questions is a grave mistake, and he must sincerely repent from it. As for his working with the certificate he obtained after graduating from the Faculty of Engineering, there is no harm in it, as long as he succeeded by his own effort in that stage.