HI,

You can choose

1) Updated virus def's.

2) Policies reviewed and updated

3) IPS and SONAR enabled with SIC

4) Latest Windows Patches.

5). Admin System Scan daily.

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

How to troubleshoot FakeAV if it is not detected

Secondly, about the Tools like Power Eraser, I would recommend you to check this Thread:

https://www-secure.symantec.com/connect/forums/need-virus-removal-tool

Security Best Practice Recommendations

http://www.symantec.com/docs/TECH91705

Best practices for responding to active threats on a network

http://www.symantec.com/docs/TECH122466

Security Response recommendations for Symantec Endpoint Protection settings

http://www.symantec.com/docs/TECH122943

Best Practice when Symantec Endpoint Protection or Symantec AntiVirus is Detecting a File that is Believed to be Safe

http://www.symantec.com/docs/TECH98360

https://www-secure.symantec.com/connect/forums/your-system-infected-symantec-tools-help-clear-infection

These are subjective and can vary from company to company. Yours is pretty standard. You many want to tighten up some other policies after the fact, eg. gpo, removable device lockdown, etc.