Also, similar to Enterprise Security, the PCI app for Splunk, and ITSI, your data will need to be normalized to conform to the Common Information Model (CIM) to integrate with DBIR. More information on CIM can be found here: Common Information Model Add-on Manual. CIM app
Based on this press release, and looking at the app, it appears using the DBIR historical data which is contained within the application itself.
There are more HTML help files in that html directory I mentioned in my answer.
If you are not familiar with CIM, then I strongly suggest you read the CIM documentation before going further with this app, since understanding how to normalize data (source typing, event types, tags), is essential.