High CPU usage because of Antimalware Service Executable

Hi,

Thank you for writing to Microsoft Community Forums.

I understand that you are facing high CPU usage because of Antimalware Service Executable. For more clarity on the issue, please respond to the questions below:

1. Which build version of Windows 10 are you using currently?

2. Are you aware of any changes made to the PC?

Refer the article to know Which version of Windows operating system am I running?

Meanwhile, I would suggest you to follow the steps mentioned below and check if that helps.

Method 1:

I would suggest you to perform a Clean Boot on the PC and check if that helps. Refer the article How to perform a clean boot in Windows.

Performing a clean boot will start the computer with minimal set of drivers and programs, to determine whether a background program is causing the issue. Some of the Startup programs will not load after performing a clean boot on the computer. However, that functionality will return when you reset the computer to start normally after finishing the troubleshooting.

Note: Please refer the section Reset the computer to start normally after clean boot troubleshooting to boot the computer in to normal mode after troubleshooting.

Method 2:

The error is mainly due to its Windows Defender real-time protection feature. Kindly follow the steps to change Windows Defender’s schedule to fix it.

1. Press Windows key + R. This will open Run. Alternatively, you can go to Start and search for Run.

2. In Run dialog box, type taskschd.msc and hit enter.

3. Navigate to Task Scheduler Library > Microsoft > Windows > Windows Defender.

4. On the right hand pane, double-click on Windows Defender Scheduled Scan.

5. On the General tab, uncheck the option Run with highest privileges.

6. Click on Conditions tab and uncheck all the options.

7. Click on OK.

If the issue persists, please get back to us with the results of troubleshooting steps to assist you better.

Regards,

Prakhar Khare

Microsoft Community – Moderator

Thank you for your response, but I figured it out. 

Actually it seems that I had an malware named exactly like the antimalware defense executable. On task manager I saw that there were two processes named the same way. One was with the Hugh CPU usage and one was the regular antimalware. I tried to change the affinity to the normal one, after I closed the one with the CPU usage and it didn't work. I didn't had permissions. Then I tried to change it to the other procesa and it worked. O right-clicked on the procesa, went to it's location and scaned the files that were exact the same (named) as the ones of The original antimalware. I stopped the procesa from the task bar and I tried to delete the .exe file. It didn't work because there were one more process that was hiding. Something like wsappx.exe. When I stopped it I could delete the exe file and the process didn't started again. I couldn't delete the folder because the malware had permission to it, so I changed them to me and I delete them. After all of that I decided to install an antivirus. I tried with Eset, didn't work, it was finishing the installation prematurely. I tried with BitDefender, it didn't work. It was blocked from the untrusted publisher list. There were a lot of antiviruses blocked, I delete them all then I tried to open the BitDefender installation. Still didn't work. I pressed Shift and right click, copied as path and went to cmd to Run it. Still didn't work, the installation was stopping at around 8%,so I gave up to install another antivirus program. I activated the windows defender one at it's max protection. Can you help me to install another antivirus software. 

P. S.: I don't want to reinstall my Windows because I've got lots of stuff. Thank you

Hello,

Try adding Antimalware Service Executable (MsMpEng.exe) to exclusion list, see if it helps:

1. Open Microsoft/Windows Defender.
2. Click on Virus & threat protection > Virus & threat protection settings.
3. Locate 'Exclusions' and click Add or remove exclusions.
4. Hit Add an exclusion and select Process in drop down.
5. In Add an exclusion, type MsMpEng.exe and click Add.

In case if you use any other anti-virus, try disabling Microsoft Defender, if it doesn't disables itself.

To help you further on this, here's the video fix:

https://www.youtube.com/watch?v=nQeM7MM6YJM

Exclusions overview: https://docs.microsoft.com/en-us/windows/security/threat-protection/microsoft-defender-antivirus/configure-exclusions-microsoft-defender-antivirus

Hope this helps!