Unfortunately I didn't get a screen capture of avast!'s notification
if you have not rebooted since it happend, you can right click avast tray icon and select show last pop up .... and take a screenshot the popup has a pin in top right corner so you can pin it to the screen if needed
This time it caught something as the logs will show.
[b]PUP[/b].RiskWare.HideExec = [b]P[/b]ossible [b]U[/b]nwanted [b]P[/b]rogram

Malwarebytes PUP Criteria https://www.malwarebytes.org/pup/

Riskware https://www.virusbtn.com/resources/glossary/riskware.xml