What is the ruling on investment funds and their returns at Commercial International Bank, especially the fixed income fund?

If the bank is usurious, it is impermissible to deposit money in it for investment or otherwise, whether in a fixed assets fund or other funds, because the investment of a usurious bank is based on usury. All its investments involve lending with interest, and their true nature is a guarantee of capital and a known profit, and this is usury, not a legitimate Mudarabah (definition) (profit-sharing partnership).