aswMBR is a anti-rootkit scanner that searchs your computer for Rootkits that infect the Master Boot Record, or MBR, of your computer. This includes the TDL4/3, MBRoot (Sinowal), and Whistler rootkits. This program will also optionally download the Avast virus definitions and do a one time virus scan for you which doesn't hurt to run but it isn't required. How to scan: Download aswMBR.exe ( 1870KB ) to your desktop. Double click the aswMBR.exe to run it If it finds something it will prompt you to take action. If it finishes and you don't see any red messages then you are good to move on to the next task. If you do get some red, then click the [Fix] for TDL4 (MBRoot) or [FixMBR] for Whistler (button select as appropriate) For more information: http://public.avast.com/~gmerek/aswMBR.htm.