What is the ruling on an accountant working in a company that sells adulterated goods, knowing that his job is limited to scheduling accounts and he has no connection to sales, and what is the ruling on a guard working in this company?

If the company's activity is limited to counterfeit goods, then working for it is never permissible. However, if it includes both permissible and counterfeit goods, then working for it is permissible, provided that your work is not related to the counterfeit goods and does not involve aiding in sin, although it is better to avoid it.