> [1] I have to assume you’re talking about some third party antimalware program because the Microsoft one absolutely does not behave how you describe.

Editing without specifying that you have edited your reply is not very good, you know. But okay.

Actually, I'm talking about the Windows-shipped Microsoft Defender process (at least it seems to come from Microsoft Defender). I have not seen anything third-party installed on my laptop at the time, and it actually behaved just like I described. I should also remind you that it is a low-end laptop, that's just Intel Core i3-N305, it's not the most powerful CPU in the world - just 8 cores, 8 threads and 3.80 GHz of max boost frequency.

If you think that I'm lying, then just search for "antimalware executable high CPU usage" in any search engine. You will find a plenty of complaints and even some guides on how to deal with it.

Does it behave like this all the time or just at specific moments?

I find on my Windows system it's only doing things when specific actions are happening.

Right now the antimalware executable process is using 196.4 MB of memory and 0% CPU for me as I type this.

When I download an executable from the Internet and run it, the CPU usage spikes to 8-10% briefly and the RAM usage goes up by 30MB or so.

I have a much higher-end CPU than that, 6 cores 12 threads (AMD Ryzen 5600X3D)

In my experience the executable is pretty much doing nothing unless I'm opening up an exe that's trying to elevate privileges or if it's doing an active periodic scan.