Trojan ZBOT with Good Rating from Symantec

Archive
1

Today i receive a spam Email (a Fake Bill) an Norton found nothing , later i check this File inside Spam and i can see Why Norton found nothing.

 

Trojan Zbot 23/46

https://www.virustotal.com/de/file/dbb8dfa4632f20e2e917be529c6ce9aea18ecb8db05c852f28ffce904e2fd3ef/analysis/1377360150/

 

And Norton say this File has Good Rating !  (see Picture)

 

http://s7.directupload.net/images/130824/p67yna4z.jpg

 

How can this happen?