What is the ruling on a head of an institution who donates from its funds to orphans and for building mosques without authorization, claiming the money is his own, for the purpose of media appearance, and then settles these donations as other purchases for the institution?

If the head of an institution is an agent acting on its behalf, and not its true owner, then it is impermissible for him to donate from its funds or spend them in ways that do not serve the interest of the work he is entrusted with, for doing so would constitute a betrayal of trust. Whatever funds he takes from the institution and spends improperly, he is obligated to return from his personal wealth.