Trojan Horse pop-up?

[ComputerDense]

Please note my user name - ComputerDense.     That will give you much info.  Anyway...

A bit ago, I got a pop-up on Avast.  It was so quick I didn't have the opportunity to read the entire thing.  However, it definitely said something about a Trojan Horse.  I'd like to think it said "blocked" but can't be certain.  Since then, I've run a quick scan but didn't see anything I could ID as abnormal but that doesn't mean much. 
Is there anything else I should do or look for?  Thanks!

Also, at the time, I was logged into a site completing an online employment application.  Again, thanks for any help/info. 

[DavidR]

Was this a pop-up in the bottom right corner of the screen ?

If so right click on the avast icon and select 'Show last popup message.@

If not open the avastUI, Real-Time Shields and you will see a wheel with all of the shields, that shows the number of files scanned and the number of detections for each. Hover the mouse over the portion of the wheel showing xxxx/1 (last scanned/last infected, for a detection) and it should show the detection information.