Before i get too deep into it, i wanted to see if it was even possible. The question is if the user's id or any sort of identifiable account information is exposed or can be retrieved in a minifilter driver.
Obviously it would probably be on me to do a lot of the legwork on actually identifying the user, but i didn't see anything that gave specific info on the user initiating the request. I ran through a few of the samples and online documentation but was unable to find a struct or anything that seemed to have any useful information.
SID - can be retrieved by the minifilter driver. Later this could help to identify user related information.
Following link has more information: