This port hijacking and backdooring is indeed dangerous, I don´t know exactly how it works, but all other aspects of Hacker Defender are harmless if you know it! I have a Process Tool which can detect Rootkit-Driver even if they are totally stealthed or rooted, it´s one of it´s kind. I think it is the only pro-gui-tool which is able to reveal them otherwise you need a external Operation System with NTFS Access on CD, that´s it. I studied Hacker Defender in the last weeks, if you know the service just do: net stop. I don´t fear it because I know it roughly and this telnet stuff or commandline intrusion I think it is very uncomfortable, newbies never would try to use this, so the danger from novices will be not that big and a good firewall will say alert when the hidden trojan wants to connect, that´s all. This commandline stuff myself I don´t like it much, I prefer GUIs in every situation.