Rkdscan is a scanner designed to detect whether or not an NT based computer is infected with the Hacker Defender root kit. To do this, it makes use of a design flaw.
You can download it from the following link: https://packetstormsecurity.com/files/download/34765/rkdscan.zip
Source: https://packetstormsecurity.com/files/34765/rkdscan.zip.html