Windows 10: Is Windows Defender Suddenly Using Constant CPU for Anyone Else?

this has just started today, I don't know if it's because of one of the Definition Updates, but Windows Defender the Antimalware Service Executable process is suddenly using 12% CPU at all timesI noticed it after doing a Full Scan and it was at a constant 6%; when I did another Full Scan, it permanently increased to 12% and is lingering there, using 500mb of MemoryI'm on Windows 10 22H2, fully up to date, and this is scaring me. my Defender and MalwareBytes scans are coming up clean and I haven't downloaded or done anything remotely suspicious or unsafe on my PCis this a bug, or is anyone el

:)

 

The "system"process is using constant CPU in windows 11

The "System" process is a core Windows process that is responsible for managing various system resources, such as the CPU, memory, and disk. It is normal for the "System" process to use some CPU resources, but if it is using a constant high CPU usage, then there may be a problem.

Here are some possible reasons why the "System" process is using constant CPU usage in Windows 11:

• Corrupt or outdated drivers: Outdated or corrupt drivers can cause the "System" process to use high CPU resources. You can update your drivers by going to the website of your computer manufacturer or device manufacturer and downloading the latest drivers for your device.
  
• Malware: Malware can also cause the "System" process to use high CPU resources. You can scan your computer for malware using a reputable antivirus program.
  
• Background processes: There may be background processes that are running and using up CPU resources. You can use Task Manager to identify and end these processes.
  
• Hardware problems: If you have recently installed new hardware, it is possible that it is not compatible with your computer and is causing the "System" process to use high CPU resources. You can try uninstalling the new hardware or updating its drivers.
  

If you have tried the above steps and the "System" process is still using constant CPU usage, then you may need to contact Microsoft support for help.

 

Windows Defender issues following Windows10 Creator Update Version 1703

Hello,

There may be a few possible reasons why Windows Defender would suddenly have performance issues. To further assess on this, kindly provide the information listed below:

• Did this issue occur only after the Creators Update?
• What are the troubleshooting steps you have done so far?
• Are you getting any error message when trying to launch Windows Defender Security Center?
• does this issue also happens to other Windows app or programs?
• What's the status of your CPU and Memory performance (Task Manager) when this issue starts to happen?

In the mean time, we suggest checking if your Windows Defender is currently on the latest version, and update it if otherwise. You can find more information about Windows Defender updates
here.

Keep us posted for any changes or outcome.

 

Windows Defender - high CPU and disk usage

Thank you very much for your quick response. I've taken all steps you suggested. This is the outcome:

• Add a process exclusion
  
  Unfortunately, this didn't work. I added both a path and a process exclusion now.The task scheduler for
• Defender looks like this for me:
  
  
  
  

• It seems no Defender tasks have run since June 30th, yet the process continues to hog the CPU
• I re-ran SFC /scannow. SFC could not find any integrity violations
• I tried disabling behaviour monitoring. The setting did not persist across a reboot, and turning it off did not make a difference while my system was still running.
  
  
  This was the output for Powershell:
  
  

PS C:\Windows\system32> Set-MpPreference -DisableBehaviorMonitoring $True

PS C:\Windows\system32> Get-MpPreference | findstr "Behavior"

DisableBehaviorMonitoring : True

PS C:\Windows\system32>

• Scanning for viruses and leftover antivirus software. This was interesting (yet unfruitful):
  
  Neither Kaspersky nor Emisoft could find any threats. MalwareBytes did find 5 executables in my temp folder, although Virustotal.com reported no danger for the files. This could mean it's a false positive, but I removed all traces of them anyway.
  
  It also found two installers (PUPs) for a Spigot toolbar, I removed those as well. They probably came with some free software package, I try to prevent installing toolbars.
• In installed AVG Anti Virus (the free version). When I rebooted after the installation, Defender was still running and taking up 25-30% of my CPU. I disabled Defender using the Group Policy editor and the service finally stopped.

AVG works for me, but like most free anti virus programs it's full of ads and "free offers" and fishy SSL/TLS interception ("web protection").

I'd like to keep using Windows Defender because it's neatly integrated into Windows 10, doesn't take a lot of resources and doesn't show annoying ads.

I hope anyone can suggest another way to fix this weird Windows Defender problem.