files detected by Avast on virustotal but not by Avast on PC

i have files from a malware pack on my pc(win 7 sp1 32bit) which i downloaded to test AVs.3 file still remains that do not get detected by Avast(using latest version & updates).however same files when uploaded on virustotal are detected as Win32:Trojan-gen & Win32:Malware-gen by Avast.these are the 3 files in question:
http://www.mediafire.com/download/cmw2ty04m6tfz8f/Trojan-Ransoms.zip
password:testing