What is the ruling on working as an accountant for an unjust sponsor who appropriates employees' money?

You are not permitted to work for your oppressive sponsor, as doing so constitutes aiding and assisting him in his injustice. Allah Almighty says: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." And Ata' said: "It is not lawful for anyone to assist an oppressor."