The genuine mrtstub.exe file is a software component of Malicious Software Removal Tool by Microsoft Corporation.
"Mrtstub.exe" is a benign Microsoft file. It exists to be downloaded with a packed file ("mrt.exe._p"), containing an updated version of the free Microsoft Malicious Software Removal Tool (MSRT), into a randomly-named folder at the root level, (e.g., "C:\d2c6febc4a2e9369b5ee1d\mrtstub.exe"), where it executes and unpacks "mrt.exe" into "C:\Windows\System32" for use. A third file named "$shtdwn$.req", whose purpose is unclear although the filename occurs with other Microsoft update downloads, also appears in this randomly-named folder. After the MSRT runs, if this folder is not automatically deleted it is safe to do so manually. If a user of Win7 (and later) has enabled Windows Update, the current month's MSRT version usually downloads on "Patch Tuesday," the month's second Tuesday. (Manual downloading is allowed.) Each month's version finds and removes only actively running, currently prevalent viruses, worms, and Trojan horses. It cannot detect spyware and is no substitute for an active antivirus program.
MRTStub stands for Malicious Software Removal Tool Update Stub
The .exe extension on a filename indicates an executable file. Executable files may, in some cases, harm your computer. Therefore, please read below to decide for yourself whether the mrtstub.exe on your computer is a Trojan that you should remove, or whether it is a file belonging to the Windows operating system or to a trusted application.
Description: Mrtstub.exe is not essential for Windows and will often cause problems. Mrtstub.exe is located in a subfolder of C:\—in most cases C:\d2cf4fd29fca9db1ed3f48\.
Known file sizes on Windows 10/8/7/XP are 91,848 bytes (10% of all occurrences), 93,368 bytes and 8 more variants.
The program has no visible window. The file is certified by a trustworthy company. The mrtstub.exe file is not a Windows core file. Therefore the technical security rating is 30% dangerous; however you should also read the user reviews.
Recommended: Identify mrtstub.exe related errors
Important: Some malware camouflages itself as mrtstub.exe. Therefore, you should check the mrtstub.exe process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.
A clean and tidy computer is the key requirement for avoiding problems with mrtstub. This means running a scan for malware, cleaning your hard drive using 1cleanmgr and 2sfc /scannow, 3uninstalling programs that you no longer need, checking for Autostart programs (using 4msconfig) and enabling Windows' 5Automatic Update. Always remember to perform periodic backups, or at least to set restore points.
Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the 6resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or, for Windows 8 and later versions, executing the 7DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.
To help you analyze the mrtstub.exe process on your computer, the following programs have proven to be helpful: ASecurity Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. BMalwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.