What is the ruling on funds deposited in a European bank that are invested in buying shares and various activities, and is Zakat obligatory on them, and how is money that is doubtful purified?

It is impermissible to deposit money in interest-based banks except out of necessity to preserve it when there is no Islamic alternative. All money must be withdrawn from the interest-based bank, and the forbidden portion (resulting from insurance shares and investment in other banks) must be disposed of by spending it on various charitable causes. Zakat is not obligatory on this forbidden money, but it is more cautious to give 2.5% of what is received from the bank for one year.