letmein telnet
http://www.windowsecurity.com/articles-tutorials/windows_os_security/Hidden_Backdoors_Trojan_Horses_and_Rootkit_Tools_in_a_Windows_Environment.html
http://www.megasecurity.org/trojans/w/winshell/Winshell5.0.html
http://www.radmin.com/download/
http://www.tightvnc.com/download.html