What is the ruling on using the funds from investment certificates whose profits have multiplied, knowing that they may be from usury (riba), and is it permissible to use them in times of need?

Haram investment certificates must be withdrawn from the bank immediately. As for the interest accrued from them, it must be disposed of by spending it on public welfare and charitable causes. A poor person in need is permitted to take from it according to their necessity, including their poor dependents.