Thanks for the clarification and further information. Interesting.
Goes to show how long I haven't looked at Ubuntu's website
No need to with Linux Lite on hand 
UPDATE: was curious, had a quick look around, and found this:
"Built-in virus protection" is a simplification of the security features of Ubuntu.
Out of interest I would reproduce the AV alert on LL, then copy the whole FF profile over to Ubuntu and run an AV test there.
Goes to show how long I haven't looked at Ubuntu's website
No need to with Linux Lite on hand UPDATE: was curious, had a quick look around, and found this:
"Built-in virus protection" is a simplification of the security features of Ubuntu.
Out of interest I would reproduce the AV alert on LL, then copy the whole FF profile over to Ubuntu and run an AV test there.