If a student cheats in his exam and passes because of that, and gets a certificate, then he gets work because of that certificate and gets a salary for that work, is this regarded as halaal? Please note that he cannot repeat the exam because he took it many years ago, and everything has changed. What should he do in order to expiate for that?
If the student cheated in the exam, and he passed because of that cheating, and got the certificate and worked because of that, and he succeeded in his work, and many years have since passed, then he has to repent and seek forgiveness from Allaah and feel regret for what has happened. For Allaah forgives and the one who repents from sin is like one who has not sinned.