mrt.exe is the process for Microsoft Windows Malicious Software Removal Tool which helps to secure your PC by removing spyware and other unwanted processes.
Microsoft Windows Malicious Software Removal Tool checks your machine for infection by specific, prevalent malicious software including Blaster, Sasser, and Mydoom. The objective of this tool is to remove the infection if it is found. Microsoft will release an updated version of this tool on the second Tuesday of each month. This tool can be downloaded as an update (kb890830)
The process mrt.exe is important for safe and secure Internet browsing and should not be terminated. MRT.exe is located in the folder C:\Windows\System32 and please note that If you find MRT.exe somewhere else other than C:\Windows\system32, then it is probably a malware application.