Hello,
Is Symantec Endpoint Protection installed with full Features?? In other words, Today installing only Virus and Spyware Protection is not enough.
https://www-secure.symantec.com/connect/articles/why-antivirus-not-enough
Secondly, to your issue check these Articles:
Scanning a file with a competitor's antivirus program detects a virus, but scanning with Symantec AntiVirus or Symantec Endpoint Protection does not
http://www.symantec.com/business/support/index?page=content&id=TECH98929
What to do when you suspect that a Symantec AntiVirus product is not detecting viruses
http://www.symantec.com/docs/TECH99222
Follow the Symantec Security Best practices - http://www.symantec.com/business/theme.jsp?themeid...
About creating a plan to respond to viruses and security risks
http://www.symantec.com/docs/HOWTO27199
Using Symantec Support Tool, how do we Collect the Suspicious Files and Submit the same to Symantec Security Response Team.
https://www-secure.symantec.com/connect/articles/using-symantec-support-tool-how-do-we-collect-suspicious-files-and-submit-same-symantec-sec
Using Symantec Help (SymHelp) Tool, how do we Collect the Suspicious Files and Submit the same to Symantec Security Response Team.
www-secure.symantec.com/connect/articles/using-symantec-help-symhelp-tool-how-do-we-collect-suspicious-files-and-submit-same-symante
Hope that helps!!