Microsoft Windows Malicious Software Removal Tool is a post-infection removal tool that checks and removes any infection found on your computer created by specific, prevalent malicious software including Blaster, Sasser, and Mydoom. If the tool did manage to find any infection on your PC, it removes and also displays a status report the very next time that you start your computer describing the outcome of the scan that includes the details of the malicious software detected and removed. The tool also creates a log file named mrt.log in the %WINDIR%debug folder.
To defend computers running Windows Operating System efficiently from the latest malicious software, Microsoft offers a new version of this Malicious Software Removal Tool every month. You can either download a copy of it manually from the Microsoft Download Center or set the Automatic Updates feature on your PC to Automatic for the newest version to automatically get delivered and installed on your computer as soon as it is released by Microsoft.
As Malicious Software Removal Tool is just a post-infection removal tool, it can never work as a replacement for an antivirus software. So, it is always recommended that you run an up-to-date antivirus software on your PC and defend your computer from all types of viruses and worms.