What is the ruling on depositing a sum of money with "Kunuz" for investment in Islamic projects, with the condition of a profit of 70% of the original amount, and "Kunuz" receiving 15% of the profit?

The aforementioned service is Islamically forbidden (haram), because among the conditions for permissible investment are that the investor does not guarantee the capital of the financier, and that the share of both parties be a common percentage of the profit, not of the capital. Therefore, stipulating a guarantee or a known percentage of the capital as profit invalidates the investment.