Here is a short list of SharePoint A/V recommended exclusions:
Drive:\Program Files\Common Files\Microsoft Shared\Web Server Extensions
Drive:\Windows\Microsoft.NET\Framework64\v2.0.50727\Temporary ASP.NET Files
Drive: \Users\service account\AppData\Local\Temp\WebTempDir
Drive\Users\the account that the search service is running as\AppData\Local\Temp
Drive:\Program Files\Microsoft Office Servers\14.0\Data. (This folder is used for the indexing process. If the Index files are configured to reside in a different folder, you also have to exclude that location.)
Drive:\Program Files\Microsoft Office Servers\14.0\Logs (If the location of log files have been changed, the new location will have to be excluded)
Drive:\Program Files\Microsoft Office Servers\14.0\Bin
Drive:\Program Files\Microsoft Office Servers\14.0\Synchronization Service
Any location you chose to store Disk-based BLOB cache.
This is based on SP2010 but should be similar in other versions as long as you update the "14" to what ever version you are running.