Black money is a term I have never heard used anywhere in English. You could call it black market money - that would be understood. We use the term 'on the black market' to refer to dealings in cash only in order to avoid tax and hide activities from the police etc. 'Dirty money' is a slang term often used, also 'laundering money' is the term used for shifting money gained illegally (e.g by drug deals) through legal activities. In the hit TV series 'Breaking Bad' the huge amounts of drug money were laundered through other businesses.