Infostealer.Bancos reported every 5 minutes and deleted

Norton Internet Security 5 for Mac. Version 12.1 (54)

 

Infostealer.Bancos reported every 5 minutes when browsing the web to trusted websites like norton.com. The file is automatically deleted and moved to /Library/Application Support/Symantec/AntiVirus/QTFiles. 

 

Is this a false-positive or is there a way to determine the source, i.e., browser, email, other computers on the network? 

Thanks.