If you keep an eye on the updates Windows installs, you may notice the Microsoft Malicious Software Removal Tool appearing every month. It removes some malware programs, but only a few — it doesn’t replace the need for an antivirus.
Microsoft’s malware removal tool exists as a sort of band-aid for the lack of antivirus in Windows. It attacks and removes prevalent malware, particularly worms, slowing their spread and preventing them from doing much more damage. It’s no substitute for an antivirus, which guards your system from a larger amount of threats, preventing them from taking root in the first place.
How the Microsoft Malware Removal Tool Works
On the second Tuesday of every month — Microsoft’s “patch Tuesday” — Microsoft releases a new version of the Microsoft malware removal tool. Windows Update downloads the updated tool, if you have it set to automatically install updates, and runs it in quick-scan mode. The tool quickly checks to see if a handful of common malware programs are running, and removes them if they are.
This tool was created by Microsoft to help counteract fast-spreading malware, such as the Blaster, Sasser and Mydoom worms, which infect a large amount of computers. Malware programs like these don’t only affect a single computer — each newly infected machine produces more traffic and infects other machines.
With the Microsoft malware removal tool, Microsoft can quickly remove prevalent strains of malware from a large number of computers at once, slowing the spread of particularly virulent malware. It mitigates the damage done by users who don’t run an up-to-date antivirus, but it doesn’t replace the need for an antivirus.
The tool has extremely significant limitations. It:
- Detects only malware that’s already infected your computer.
- Removes only a few strains of malware.
- Detects only malware running on your system.
- Updates and scans your system only once per month.
Why You Still Need An Antivirus
Antivirus programs are the mirror image of the Microsoft Malware Removal Tool. They:
- Prevent malware from running in the first place.
- Try to detect every known malware program.
- Scan your entire system for malware that may be hiding on your file system, but not actively running.
- Run all the time, updating once per day — or more.
Running It Manually
While Microsoft’s malware removal tool usually runs in quiet mode, with no user intervention, you can also run it manually. Type “mrt” into the search box in the Start menu press Enter to run the mrt.exe file.
If the tool is more than 60 days old, it will prompt you to download a newer version. As you can see, Microsoft recommends running an antivirus product instead.
Click the “View a list of malicious software that this tool detects and removes” link and you’ll see a short list of malware. You can also view this list on Microsoft’s website.
From this window, you can do a full scan of the files on your computer instead of just doing the standard “quick scan.” To be honest, there’s not much value in running the full scan. If you’re going to do a full, in-depth scan, you should do it with a complete antivirus program. The full scan still only detects a few types of malware.
If you do a scan, you’ll hopefully see a message saying “No malicious software was detected.” As the tool only checks for a few types of malicious software, you can’t be sure that no malicious software is present on your system.
Using An Antivirus Program
Microsoft provides their own free antivirus program, Microsoft Security Essentials, which you can download from Microsoft’s website. You can also use another free antivirus program instead. The Microsoft Malware Removal Tool isn’t good enough to rely on.
Windows 8 will have a built-in antivirus program, eliminating the need for Microsoft’s malware removal tool.
Do you use Microsoft Security Essentials, or do you prefer another antivirus product? Leave a comment and let us know.