No malware found with Malwarebytes, yet warnings still there?

Last month, my MacBook got malware, so I ran Malwarebytes, which didn't find anything.

Still the warnings at the begining of each time the MacBook being turned on, warnings displayed right below the upper right hand corner, as well as popping them from time to time while I was using the laptop.

I called the Support. Not sure why yet the tech asked me to run Malwarebytes too, and then asked me to clear the browsing history. That's when no more warnings shown.

I got these warnings again (seem like always about McAfee). What's up with AcAfee????? on the Labord Day. I mimiced what the apple tech asked me to do, as well as cleared the browsing history. Unfortunately, it does not seem working this time.

I hate to call the suppoprt again, although it doesn't hurt. I prefer to find out if I can rid of the malware myself first before I need to call again.