Is it permissible to receive a large prize amount from an alcohol company, even if it is intended to be spent on good causes?

If the prize is a gift from a company whose entire wealth is unlawful (from selling and manufacturing alcohol), then it must be disposed of and spent on the welfare of Muslims or given to the poor and needy. It is not permissible to take from it unless you are poor and in need, in which case you may take only what you need. However, if the company's wealth is mixed (some lawful and some unlawful), and the prize was won through a legitimate means without gambling, then there is no harm in benefiting from it.