Is Zakat obligatory on salaries earned from working in usurious banks, and how is it to be paid if it reaches the nisab?

It has been previously clarified that working in usurious banks is unlawful, because it constitutes cooperation in sin, and the money derived from it is unlawful. Therefore, whoever works therein must repent to Allah and cease this work. Zakat (definition) is not obligatory on the money resulting from this work because it is not his rightful possession. Rather, he must dispose of it by spending it on charitable causes and for the benefit of Muslims.