Suspicious Group And Account Reconnaissance Activity Using Net.EXE

detection:
  filter_group_add:
    CommandLine|contains: ' /add'
  selection_accounts_flags:
    CommandLine|contains: ' /do'
  selection_accounts_root:
    CommandLine|contains: ' accounts '
  selection_group_flags:
    CommandLine|contains:
      - 'domain admins'
      - ' administrator'
      - ' administrateur'
      - 'enterprise admins'
      - 'Exchange Trusted Subsystem'
      - 'Remote Desktop Users'
      - 'Utilisateurs du Bureau à distance'
      - 'Usuarios de escritorio remoto'
      - ' /do'
  selection_group_root:
    CommandLine|contains:
      - ' group '
      - ' localgroup '
  selection_img:
    - Image|endswith:
        - '\net.exe'
        - '\net1.exe'
    - OriginalFileName:
        - 'net.exe'
        - 'net1.exe'
  condition: selection_img and ((all of selection_group_* and not filter_group_add) or all of selection_accounts_*)

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 Florian Roth (Nextron Systems), omkar72, @svch0st, Nasreddine Bencherchali (Nextron Systems), 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.

None of the everyday examples and documented commands on CmdID’s program pages trips it. To see whether a command line does, paste it into CmdID.