Windows 10: Something interfering with Defender and taking up my CPU

Hey, I've had some problems with my computer recently. Specifically:


-My computer runs at essentially "full capacity" at most times, with my CPU going at 100% whenever I am not checking on it through task manager, at which point the percentage drops suddenly, as if something was hiding from it.


-I've tried factory resetting essentially a clean install, removing all my other files, upon which near completion the process suddenly stops with an "unknown error" and boots back up to login screen.


-I've tried scanning with Defender, with which the quick scan will work, but full scan and offline scan never complete and corresponding logs never get produced


-I've tried using trusted 3rd party resource monitors, which some have been able to generally locate where the virus is from but can never find the .exe or file running it.


I'm usually pretty careful with stuff, so I'm pretty convinced it's a virus. Perhaps an invasive cryptominer or something. Could I get some help?

:)

 

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.

 

AMD FX OC'ers Club

That's what the auto setting will do since you're over the 1333 mark it jumps to the next step which isn't listed or officially supported I assume by that ram.

At this point though I would suggest dropping the multi one step or .5 so that we can get something stable and possibly take the heat issue out of the picture for now.

 

Antimalware Service Executable taking up high CPU for several hours!

No, it usually did not for me either, until today.

Posting system specs is a little off-topic, because my problem is that even though I do this step:
https://support.microsoft.com/en-us/...nder-antivirus

- The Antimalware Service Executable still runs high. I have a pretty good CPU and this has never been a problem until today.

My computer is neither new or old. It was installed 1½ years ago. I never had any problems until today.

I did this step:

That "note" is my problem... it still scans, and it is still scanning while I am writing this.

I already set the Exclusions to the Windows Defender path. Did not work either.