And PUP:Win32:InstalleRex-CE[PUP] and PUP:Win32:InstalleRex-BV[PUP] with severity low.
PUP = not virus / Possible Unwanted Program .... usually crap programs that comes bundled with freeware downloads
One of the problem is, I always download the files into a same folder and have Avast scan over that folder every time I downloaded something new.
not necessary as avast realtime protection have already scanned it when downloaded however no security program have 100% detection so you can upload and test file at online multiengine scanners like these www.virustotal.com / www.metascan-online.com / www.jotti.org
Why Avast can't detect its a trojan when I downloaded the program? I just get to know the file is infected with a Trojan after I run a full scan today.
as said, no security program have 100% detection ..... if they did there would not be a virus problem maybe avast recived signature for it after you downloaded it.... maybe it is a avast False Positive .... test file at above given link(s)