Is money earned from salary permissible (halal) or forbidden (haram) if it is spent entirely despite absence from work without that being recorded, and is it permissible to give it to a indebted father if it is forbidden and cannot be returned?

As long as the salaries were disbursed to you by order of the company's senior management, there is no harm in benefiting from them and spending them as you wish. Giving money to your father to pay off his debt is permissible, but it is not permissible to pay off usurious interest on his behalf.