More serious than
作弊 (zuòbì) 'to cheat (in tests, games)' —
舞弊 is the formal / legal term covering exam cheating, electoral fraud, accounting fraud, and procedural rigging. Common compounds:
营私舞弊 'to engage in graft for personal gain',
考场舞弊 'exam-hall cheating',
徇私舞弊 'malpractice for private favor'.