Can't delete some files on Windows shares to TrueNAS

Using TrueNAS core 13.3. I have multiple shares configured in Windows 10 to access TrueNAS pools. From Windows there are some files (like RDOS.DOS) which I cannot delete due to access denied. I have tried changing security setting of the files within Windows but am also not allowed. How can I do this locally (maybe with SSH)? Or is there some magic within Windows?