What is the ruling on working and on the money earned from a job obtained through deception, knowing that the employee does not perform essential work and was initially unaware of how she was employed?

If the job is a fraud to unlawfully take public money, then the manager has committed treachery and must repent, and the employee must leave the job and return what she has taken. However, if there is actual work, but it is little, then the job and the salary are permissible; because the employee deserves the wage by dedicating herself and being present during official working hours, even if the work is little.