Strange (spam?) Apps in Mac Notifications, cannot find, how to remove?

Recently bought Macbook Pro 2020 M1, Sonoma 14.6.1.

The MacBook started getting unwanted onscreen notifications about viruses. In Preferences>Notifications, I found odd named items 'resertol.co.in' and 'antivirusarmorhub.xyz', and turned their notifications off. That seems to have stopped that annoyance.

But how do I remove those 'apps' (resertol, antivirus..) from that notification list and the Mac? They do not show up in Applications.

(I'm more used to an old Catalina mac, which I'm typing on now; I don't know where else to search in the Sonoma MacBook to find and trash the bad apps.)

Also, I saw a discussion recommending Malwarebytes for Mac. So I installed successfully on MacBook, free from App Store; it's in Applications, but how do I run it, or know if it's accomplishing anything? I hoped it might find and delete those spam apps (or whatever they are.) Thanks.