Can a pre-existing malware "hide" from this anti-virus program or disrupt its process?

I installed this product on both my iMac and my MacBook. I suspect that one of these had been infected by malware.

I ran the program on the iMac with no problem and was informed there were no threats.

WhenI tried to run the program on the laptop, the first two times I tried, the program quit spontaneously and the icon disappeared from the menu bar.

I shut down the laptop and restarted it later on. I again tried to run the program and it ran and seemed to end too quickly and the "box" on my screen said the program had never been run. I repeated the process a second time with the same results. The third time I tried it, the scan seemed to be operating normally and when it finished, I did get the notification that the scan was run on May 4 at whatever time and that no threats were uncovered.

The way this process unfolded has me thinking that whatever malware may be on my laptop was able to corrupt the anti-virus program so that it could not be detected. Is this possible? And what should I do if that's the case?