SharePoint - AV scanning SharePoint.

Make sure you tell it to ignore your search indexes and other SharePoint areas!
See: http://support.microsoft.com/kb/952167

To be sure it is not hitting your index location, you can check where that is currently set by:

Central Admin -> Application Management -> Manage service applications
   -> Search Service Application ->Search Application Topology (Modify)
      -> IndexPartition/Query Component (Edit Properties).

Or via PowerShell, run the SharePoint 2010 Management Shell command:

   $(Get-SPEnterpriseSearchServiceInstance).CrawlComponents.Item(0).IndexLocation