Is it permissible to harm one who has wronged me, usurped my effort, and attributed it to himself?

It is not permissible for a Muslim to harbor resentment towards his Muslim brother or to intend evil for him. Rather, he must be pure of heart, forgive, and do good, for Allah Almighty says: "Hold to forgiveness, command what is customary, and turn away from the ignorant" and "So whoever pardons and makes reconciliation - his reward is due from Allah." The Prophet, peace and blessings be upon him, forbade suspicion, spying, envy, and hatred, and commanded us to be servants of Allah, brothers. If a Muslim has a right, he may demand it through legitimate means without harming others.