Infected with virus alerts on Safari 18.6 with Malwarebytes and Spectrum Security Suite

You have allowed a website to send you those Notifications. Open Safari and go to Safari > Settings > Websites > Notifications, and remove all sites you see there. Problem Solved!

There is nothing wrong with your Mac, you simply allowed a website to send you those, and they used that opportunity to scare you into downloading some software or sign up for a service to solve a problem you do not have. Nothing more than an advertisement.

Note that Safari will prevent you from accessing any unsecured "http" site, even without MalwareBytes or Spectrum Security.

Yeah. Somewhere along the path you were offered notifications, and had accepted those notifications. You now no longer wish to receive those notifications. No ”virus”, no hacker, no compromise here, nothing but breathless advertising using words specifically intended to trigger panic and fear, and to unlock profit for the advertiser.

Here is how to shut off these notifications, and how to block any further solicitations for permission to send these:

Stop unwanted Notifications - Apple Community