Antivirus events Remove Failure

I have been using Comodo for Mac for a few months now & today received my first alert. From the offered options I selected “remove”. The resulting screen shows Detect Success, Ask Success, and Remove Failure. Could someone please tell me exactly what this means and any necessary steps I should be taking to rid my computer of this virus. I assume this means that Comodo wasn’t able to remove the virus. Is that correct? Should I not have selected “remove”? Would quarantine have been a better option. Believe it or not I got this virus while downloading coloring pages for my grandson. Obviously this relatively non savvy, senior computer user would greatly appreciate any help/advice. Thanks in advance.

The name of the Malware seems to be ApplicUnwnt@321020484 and the location appears to be Volumes/Installer/Installer.app
I also ran a scan a few minutes ago which shows no threats. I’m a bit confused.