Omid Farhang
SysDefenders is a rogue security product in the WiniGuard family — another early-2010 rebrand in a line that was already spinning out new names every few days by late 2009 (The biggest rogue family).
Same playbook: fake infection results, scare warnings, and a paid unlock that does not protect the machine. Do not buy it. If it is installed, follow the Malware Removal guide for Windows.