unethical — lacking moral principles; unwilling to adhere to proper rules of conduct.
corrupt — Someone who is corrupt behaves in a way that is morally wrong, especially by doing dishonest or illegal things in return for money or power.
dishonest — not honest; disposed to lie, cheat, or steal; not worthy of trust or belief: a dishonest person.
immoral — violating moral principles; not conforming to the patterns of conduct usually accepted or established as consistent with principles of personal and social ethics.
improper — not proper; not strictly belonging, applicable, correct, etc.; erroneous: He drew improper conclusions from the scant evidence.
unjust — not just; lacking in justice or fairness: unjust criticism; an unjust ruler.
unrighteous — not righteous; not upright or virtuous; wicked; sinful; evil: an unrighteous king.