WmiPrvSE Suspicious Child Process (Sysmon)

id: '25922.47939'
title: WmiPrvSE Suspicious Child Process
description: Windows Management Instrumentation Provider Service (WmiPrvSE.exe) is
  a Windows component used for system management, monitoring, and reporting. While
  it is legitimately used by system administrators, its system privileges make it
  an attractive target for abuse by threat actors. This use case detects unusual child
  processes of WmiPrvSe.exe. It specifically looks for instances where known scripting
  or executable processes are spawned by WmiPrvSe.exe. The rule excludes certain system
  processes like 'werfault' and 'wmiprvse' and specific user accounts to reduce false
  positives, focusing on patterns that are often associated with security threats
  or attacks. Living Off the Land Binary and Scripts (LOLBAS) (LOLBIN)
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "<EventID>1<")
  (TERM(wmiprvse) OR "wmiprvse.exe") (TERM(certutil) OR TERM(cscript) OR TERM(mshta)
  OR TERM(msiexec) OR TERM(regsvr32) OR TERM(rundll32) OR TERM(verclsid) OR TERM(wscript)
  OR "certutil" OR "cscript" OR "mshta" OR "msiexec" OR "regsvr32" OR "rundll32" OR
  "verclsid" OR "wscript") | where match(parent_process_path, "(?i)(\x5cwbem\x5cwmiprvse\.exe)")
  and (match(process_name, "(?i)(certutil|cscript|mshta|msiexec|regsvr32|rundll32|verclsid|wscript)\.exe")
  or match(process_name, "(?i)cmd\.exe") and match(process, "(?i)(cscript|mshta|powershell|pwsh|regsvr32|rundll32|wscript)"))
  and not match(process_name, "(?i)(werfault|wmiprvse)\.exe") and not match(user,
  "AUTHORI|AUTORI") | table _time, host, user, process, process_*, parent_process_*
  | bin span=1s | stats values(*) as * by _time, host '
techniques:
- execution:windows management instrumentation
technique_id: 
- T1047
data_category:
- Windows Sysmon
references:
- https://thedfirreport.com/2021/03/29/sodinokibi-aka-revil-ransomware/
- https://blog.osarmor.com/319/onenote-attachment-delivers-asyncrat-malware/