Is it permissible to continue working in a company that has begun manufacturing harmful equipment, knowing that one relies on its salary for a living?

If your work in the company causes harm and injury to people without a legitimate شرعي reason, then it is not permissible for you to continue in it, due to the Prophet's (peace be upon him) saying: "There should be neither harming nor reciprocating harm," and Allah's Almighty saying: "And do not cooperate in sin and aggression." However, if your work is not connected to that, then there is no blame upon you for continuing in it.