New User Created Via Net.EXE
A Sigma rule for process creation on Windows, by Endgame, JHasenbusch (adapted to Sigma for oscd.community).
medium 1 ATT&CK technique 3 programs it names 2 everyday examples trip it
What it looks for
detection:
selection_cli:
CommandLine|contains|all:
- 'user'
- 'add'
selection_img:
- Image|endswith:
- '\net.exe'
- '\net1.exe'
- OriginalFileName:
- 'net.exe'
- 'net1.exe'
condition: all of selection_*
The rule’s detection, its selections and fields in order of name. The whole rule, with its references and false positives, is on SigmaHQ, by Endgame, JHasenbusch (adapted to Sigma for oscd.community), under the Detection Rule License 1.1. CmdID evaluates it on a command line alone: a test on what a command line cannot show, such as the parent process or the user, is not met.
Command lines that trip it
Add a user to the local security group (run in elevated console) on the page for net
net localgroup "Administrators" username /addIdentifyTo add a user account for Jay Samson (user name: jays), with sign in rights from 8 AM to 5 PM, Monday through Friday, with the mandatory password Cyk4^g3B, and use the user's full name, run the following command on the page for net user
net user jays Cyk4^g3B /add /passwordreq:yes /times:monday-friday,8am-5pm /fullname:"Jay Jamison"Identify