Antimalware Service Executable constantly running

Brumboy · 31 Jul 2018 at 19:54

Hi,

So for the past week, Antimalware Service Executable has started to constantly run in the background.

As soon as I turn the PC on, it keeps spiking up using up to 30% CPU usage.

Even with no programs running it does this, causing the PC to slow down.

I have changed nothing. I have no idea what is causing this but it's really annoying.

Any idea's how to stop it?

Thanks!

Rroff · 31 Jul 2018 at 20:08

Had that happen twice after 1803 update on Windows 10 - on one system it stopped doing it after I left the system idle for like 40 minutes on the other it just carried on indefinitely and I eventually found it had got itself in a loop trying to update and install a signature update

which took a lot of manually messing about to force it to retry from scratch.

It also seems to like to kick in a lot more since 1803.

andshrew · 31 Jul 2018 at 21:54

It should always be running because it's the Windows Defender service.

I would start by looking in the Event Log to see if that reveals what it is actually doing:
Microsoft-Windows-Windows Defender/Operational

Glanza · 1 Aug 2018 at 08:48

I've found in the past that to get it back behaving you need to run a manual virus scan in windows defender.

Brumboy · 4 Aug 2018 at 11:14

Sorry for the late reply!

I have done all the above checks and nothing stands out. I have ran a complete scan and the service still spikes to 30% almost constantly slowing down the entire system.

I have disabled it too and that doesn't even stop it from running which is strange?

Any other idea's?

Rroff · 5 Aug 2018 at 12:42

It is possible like I had with a stuck signature update that constantly went around in a loop of trying to update the definitions - but I don't know exactly what I did to fix it - went through a cocktail of different things and eventually something sorted it.