It seems me that it is a “false positive”.
Win Rar v.3.30 (English)- installation file Winrar.exe is recognized by Avast as Win32:Trojan-gen. {Other}
You can download from:
http://www.winrar.it/ (WinRAR 3.30 per Windows 95/98/Me/NT/2000/Xp/2003 Inglese)
or direct link:
http://www.winrar.it/prelievo.php4?url=http://www.rarlab.com/rar/wrar330.exe
Regards
Avast VPS: 432-1