prompt SQL Script: Check for hidden database user
prompt 
prompt Version:  0.01 
prompt Autor:    Alexander Kornbrust of Red-Database-Security GmbH
prompt
prompt These SELECT statements should never return anything
prompt Keep in mind that an empty result does not guarantee that your 
prompt data dictionary is not modified. You can check the integrity of your data dictionary with Repscan 
prompt       http://www.red-database-security.com/repscan.html
prompt 
select name "Invisible User in DBA_USERS" from sys.user$ where type#=1 minus select username from SYS.dba_users;
select name "Invisible User in ALL_USERS" from sys.user$ where type#=1 minus select username from SYS.all_users;