i got a file from someone that seems to be safe by norton and also windows antivirus, but when i did a scan online (from other site)just to be sure that the file is really safe, they found that the file contain ** Trojan:MSIL/Kryptik.AAU!MTB ** something that Norton should finds and make an alert
if i was opening it , my pc will be infected and i couldn't know that.
i know that isn't possible to make 100% protection, but i guess more updates?