Windows Malicious Software Removal Tool
Encyclopedia
Microsoft Windows Malicious Software Removal Tool is a freely-distributed
virus removal tool developed by Microsoft
for the Microsoft Windows
operating system. First released on January 13, 2005, it is an on-demand anti-virus tool that scans the computer for specific widespread malware
and tries to eliminate the infection. It is automatically distributed to Microsoft Windows computers via Windows Update
service but can also be separately downloaded.
The program is usually updated on the second Tuesday of every month
and distributed via Windows Update
, at which point it runs once automatically in the background and reports if malicious software is found. Alternatively, users can manually download this tool from Microsoft Download Center. It records its results in a log file located at %windir%\debug\mrt.log. To run it manually at other times, users can start "mrt.exe" using the Command Prompt
or Run command
in the Start Menu
.
As released, the tool is configured to report anonymized data about infections to Microsoft if any are detected. The reporting behavior is disclosed in the tool's EULA, and can be disabled if desired.
In a June 2006 Microsoft report, the company claimed that the tool had removed 16 million instances of malicious software from 5.7 million of 270 million total unique Windows computers since its release in January 2005. The report also stated that, on average, the tool removes malicious software from 1 in every 311 computers on which it runs. As of Microsoft claims that the software has removed password stealer
threats from 859,842 machines.
Freeware
Freeware is computer software that is available for use at no cost or for an optional fee, but usually with one or more restricted usage rights. Freeware is in contrast to commercial software, which is typically sold for profit, but might be distributed for a business or commercial purpose in the...
virus removal tool developed by Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
for the Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
operating system. First released on January 13, 2005, it is an on-demand anti-virus tool that scans the computer for specific widespread malware
Malware
Malware, short for malicious software, consists of programming that is designed to disrupt or deny operation, gather information that leads to loss of privacy or exploitation, or gain unauthorized access to system resources, or that otherwise exhibits abusive behavior...
and tries to eliminate the infection. It is automatically distributed to Microsoft Windows computers via Windows Update
Windows Update
Windows Update is a service provided by Microsoft that provides updates for the Microsoft Windows operating system and its installed components, including Internet Explorer...
service but can also be separately downloaded.
The program is usually updated on the second Tuesday of every month
Patch Tuesday
Patch Tuesday is usually the second Tuesday of each month, on which Microsoft releases security patches.Starting with Windows 98, Microsoft included a "Windows Update" system that would check for patches to Windows and its components, which Microsoft would release intermittently...
and distributed via Windows Update
Windows Update
Windows Update is a service provided by Microsoft that provides updates for the Microsoft Windows operating system and its installed components, including Internet Explorer...
, at which point it runs once automatically in the background and reports if malicious software is found. Alternatively, users can manually download this tool from Microsoft Download Center. It records its results in a log file located at %windir%\debug\mrt.log. To run it manually at other times, users can start "mrt.exe" using the Command Prompt
Command Prompt
Command Prompt is the Microsoft-supplied command-line interpreter on OS/2, Windows CE and on Windows NT-based operating systems...
or Run command
Run command
On the Microsoft Windows operating system, the Run command is used to directly open an application or document whose path is known. It functions more or less like a single-line command line interface....
in the Start Menu
Start menu
The Start Menu and Start Button are user interface elements used in the later versions of the Microsoft Windows operating systems and in some X window managers...
.
As released, the tool is configured to report anonymized data about infections to Microsoft if any are detected. The reporting behavior is disclosed in the tool's EULA, and can be disabled if desired.
In a June 2006 Microsoft report, the company claimed that the tool had removed 16 million instances of malicious software from 5.7 million of 270 million total unique Windows computers since its release in January 2005. The report also stated that, on average, the tool removes malicious software from 1 in every 311 computers on which it runs. As of Microsoft claims that the software has removed password stealer
Keystroke logging
Keystroke logging is the action of tracking the keys struck on a keyboard, typically in a covert manner so that the person using the keyboard is unaware that their actions are being monitored...
threats from 859,842 machines.