You can take an open source rat from github and eliminate the need for port forwarding through certain services which allow you to get a connection to whoever runs your executable (some rats come with this feature built-in) without needing to know their ports etc. The primary problem would be making it fud, you need to either make, update or purchase a crypter that will make the rat UD. As for doing this anonymously, I don't think most rats have operational security features although there are exceptions, you need to figure out how to maintain your anonymity.