How can training employees on a payroll disbursement program be permissible (halal), while the repair and maintenance of ATM machines belonging to banks from which they will withdraw their salaries be impermissible (haram)?

The basic principle is that it is permissible to repair any machine, as this is a lawful act. However, repairing a machine belonging to an interest-based (riba) bank is prohibited because it assists in the bank's continued operation, increases its popularity, and facilitates forbidden contracts with it. Similarly, training employees in a way that facilitates their receipt of government salaries is permissible, even if done through the bank's machine, but working in the maintenance of this machine is prohibited. As for transferring money through the bank, it is permissible, while working as an employee in the bank is prohibited, even if one performs a permissible task, because it assists the bank in its forbidden activities and implies approval of the evil within it. Therefore, it is not permissible to work in an interest-based bank in any position, even if the role itself is not interest-related, such as guarding or cleaning, because that is considered cooperation in sin and aggression.