Is an employee who steals from his employer due to low wages and exploitation by the employer obligated to confess and return the money, or should he continue with his actions?

It is not permissible for a worker to steal from their employer's money under the pretext of low wages, because theft and betrayal are among the major sins and injustices. Allah has threatened the thief with punishment in this world and the Hereafter. The thief must repent and return what they took to its owner. If it is difficult for them to inform the employer, they can return the money to him indirectly.