CmdID

CmdID / Rules / Windows

Suspicious WmiPrvSE Child Process

A Sigma rule for process creation on Windows, by Vadim Khrykov (ThreatIntel), Cyb3rEng, Florian Roth (Nextron Systems).

high 3 ATT&CK techniques 11 programs it names

What it looks for

its detection, as SigmaHQ writes it
detection:
  filter_main_msiexec:
    CommandLine|contains: '/i '
    Image|endswith: '\msiexec.exe'
  filter_main_werfault:
    Image|endswith: '\WerFault.exe'
  filter_main_wmiprvse:
    Image|endswith: '\WmiPrvSE.exe'
  selection_children_1:
    Image|endswith:
      - '\certutil.exe'
      - '\cscript.exe'
      - '\mshta.exe'
      - '\msiexec.exe'
      - '\regsvr32.exe'
      - '\rundll32.exe'
      - '\verclsid.exe'
      - '\wscript.exe'
  selection_children_2:
    CommandLine|contains:
      - 'cscript'
      - 'mshta'
      - 'powershell'
      - 'pwsh'
      - 'regsvr32'
      - 'rundll32'
      - 'wscript'
    Image|endswith: '\cmd.exe'
  selection_parent:
    ParentImage|endswith: '\wbem\WmiPrvSE.exe'
  condition: selection_parent and 1 of selection_children_* and not 1 of filter_main_*

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 Vadim Khrykov (ThreatIntel), Cyb3rEng, Florian Roth (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.

Programs and files it names

their pages here

ATT&CK

the techniques it is tagged with
T1047Windows Management Instrumentation
T1204.002User Execution: Malicious File
T1218.010System Binary Proxy Execution: Regsvr32