The objectSID is not being scanned from AD user accounts. We only scan the attributes which you can find in tblADusers. We recommend having a look at the Database Dictionary which is accessible at the top of the report editor for a list of fields which are available in the Lansweeper database.
Note: Lansweeper scans the SID of local user accounts. You can get it into a report by adding tblUsers to your report and selecting tblUsers.SID to be displayed.