I'm using Win10 home 10.0.19042 Build 19042 on a Dell Inspiron 5482 (x64) with a i7-8565 CPU (@ 1.8 GHz, 4 core, 8 logical processors). More than enough RAM/ROM and free space to run all current processes at once.
Recently, Immunet's CPU usage goes as high as 90%. This used to be random and infrequent - I didn't think much of it. Now it happens semi regularly. I tried a full scan via immunet and a full scan via windows defender and both turned up nothing. There's no other issues on my PC at the moment. There is no particular process that triggers this - it may or may not trigger for any given process. It may or may not happen when an application starts running. It once happened when my PC was idling with no applications open and few extraneous background processes (I was getting ready to run a resource intensive program when this happened - I went as far as to have minor background processes like Adobe acrobat update service, Windows search indexer, etc. turned off)
There isn't any particular accompanying spike in disk usage.
In task manager, the spiked CPU is present in "Cisco AMP for Endpoints Connector" process, which has a "Immunet 7.4.0" subprocess.
I have verbose tray notifications enabled and there is no notification. I am usually not in gaming mode or focus mode. Checking history or summary doesn't show many recent events, the most recent ones typically being spread out over the last few minutes, all of then a green tick.
I have the following settings ENABLED in Immunet:
Monitor Program Install
Monitor Program Start
Enable ClamAV Engine
Allow Definition Updates
On Detection of Malicious Files
On Detection of Suspicious Files
Scan Archive Files
Scan Packed Files
Verbose Tray Notifications
Service status: Started
Debug logging status: Started
Note that Notification/Gaming mode is off (tbh never turned it on before) and that Misc/send files to Immunet for analysis is off (this one I regularly flip based on circumstances, doesn't really make a difference in the frequency afais)
Finally: I'm not sure what versions I had before. I regularly click the "Update now" button on the menu but idk if that only updates the definitions or immunet itself as well.
I only have immunet installed. I also use windows defender as a second layer because it's present.
Finally, I found similar posts here, but they are all relatively different. Some mention a increase in CPU usage in a different process, some report a disk usage increase, some say it happens only when certain apps run, etc. whereas mine happens randomly and for no apparent reason.