Kacak is a tool that can enumerate users specified in the configuration file for windows based networks. It uses metasploit smb_enumusers_domain module in order to achieve this via msfrpcd service. If you are wondering what the msfrpcd service is, please look at the https://github.com/rapid7/metasploit-framework/blob/master/documentation/msfrpc.txt . It also parse mimikatz results.