LoFP / administrators may leverage wwmi and powershell.exe to start a process on remote systems, but this activity is usually limited to a small set of hosts or users.

Techniques

• T1047

Sample rules

Remote Process Instantiation via WMI and PowerShell

• source: splunk
• technicques:
  • T1047

Description

The following analytic detects the execution of powershell.exe using the Invoke-WmiMethod cmdlet to start a process on a remote endpoint via WMI. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and process telemetry. This activity is significant as it indicates potential lateral movement or remote code execution attempts by adversaries. If confirmed malicious, this could allow attackers to execute arbitrary code on remote systems, leading to further compromise and persistence within the network.

Detection logic

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_powershell` (Processes.process="*Invoke-WmiMethod*" AND Processes.process="*-CN*" AND Processes.process="*-Class Win32_Process*" AND  Processes.process="*-Name create*") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)` 
| `remote_process_instantiation_via_wmi_and_powershell_filter`

Remote Process Instantiation via WMI and PowerShell Script Block

• source: splunk
• technicques:
  • T1047

Description

The following analytic detects the execution of the Invoke-WmiMethod commandlet with parameters used to start a process on a remote endpoint via WMI, leveraging PowerShell Script Block Logging (EventCode=4104). This method identifies specific script block text patterns associated with remote process instantiation. This activity is significant as it may indicate lateral movement or remote code execution attempts by adversaries. If confirmed malicious, this could allow attackers to execute arbitrary code on remote systems, potentially leading to further compromise and persistence within the network.

Detection logic

`powershell` EventCode=4104 ScriptBlockText="*Invoke-WmiMethod*" AND (ScriptBlockText="*-CN*" OR ScriptBlockText="*-ComputerName*") AND ScriptBlockText="*-Class Win32_Process*" AND ScriptBlockText="*-Name create*" 
| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer UserID
|  `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `remote_process_instantiation_via_wmi_and_powershell_script_block_filter`