Looking for the owners of money and repaying them or giving the money in charity on their behalf
In case that you do not know the people to whom this money is due after
looking for them and exploring the matter, it is obligatory on you that you give such money in Sadaqah (voluntary charity) on their behalf. Only doing so will discharge you of responsibility. (Part No. 14; Page No. 77) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.