With the July 2014 CU for SharePoint 2013, you can yet again install your custom PDF iFilter, or override any built-in handler to use the iFilter of your choice.
If you previously ran the command Get-SPEnterpriseSearchFileFormat -SearchApplication $ssa -Identity pdf. You would see the following output.
Identity : pdf Name : PDF MimeType : application/pdf Extension : .pdf BuiltIn : True Enabled : True
After applying the July 2014 CU you get this instead
Identity : pdf Name : PDF MimeType : application/pdf Extension : .pdf BuiltIn : True Enabled : True UseIFilter : False
Notice the last line which says UseIFilter. In order to turn on iFilter support for PDF processing, use the commandlet Set-SPEnterpriseSearchFileFormatState which has an added switch –UseIFilter for this purpose.
The full command to switch to iFilter for PDF is listed below, and you can use a similar command for any iFilter you want to replace – but remember to install the iFilter properly first.
Set-SPEnterpriseSearchFileFormatState -SearchApplication $ssa -Identity pdf -UseIFilter $true -Enable $true
SharePoint Server 2013 July 2014 CU Download
SharePoint Foundation 2013 July 2014 CU Download
Implement a custom iFilter in SharePoint 2013
Thanks to Neil Hodgkinson for informing me of this file format change :)