Is working for a company that develops software for combating money laundering and suspicious transfers, used by both Islamic and interest-based banks, impermissible (haram) or permissible (halal)? And if it is deemed impermissible, what should be done with the money earned during the period of searching for another job?

There is no objection to working with the aforementioned program at the company, nor to selling these programs to banks and financial institutions, because their benefit is general and their utility extends to society, whether it is for monitoring suspicious accounts, or preventing money laundering and tracking transfers. Accordingly, there is no objection to your work as a quality auditor for programs that combat financial crimes, and you are not required to dispose of your salary.