Is there a way to pull the windows AD users list and their attributes from BIRT iHUb16.4? If yes, is there a sample report that achieves this?
You need to create your own jar that gets the data from AD and outputs it in a useful format. Then create a report with a Scripted data set that calls the jar to get the data. Information Hub has the ability to communicate with AD via the Report Server Security Extension (RSSE). Parts of it could possibly be used as a template for your jar, but it's designed for iHub security, not for generating report data.
I'm sure this goes without saying, but I'll say it anyway. Creating a report that displays AD user data would be a security risk. You could set permissions so that it can only be run by an admin, but the data could be exported, the report could be left open, etc.