TSGrinder is a fairly old program that brute forces Microsoft RDP servers, Are 2000, XP or 2003, To download from HERE. Works by command line:

The first thing we have to have is a dictionary with the possible passwords that we want from the user to attack, the most logical thing would be to attack the Local Administrator, since it is an account that is not blocked after several incorrect 'logon' attempts. Then on the command line: tsgrinder -w DICTIONARY -u Server AdministratorRDP

We must be patient because the execution of the program is very slow and more so if the speed between the Terminal Server and the client is slow, first this screen will load and after a while it will automatically enter the Username and password.

Normally you will get this error because the password is invalid, but we do have the good one in the dictionary.. It's a matter of waiting!

In my example after a while you can see that he takes out the correct password and marks it as “success!”