Remote Process Instantiation via WMI and PowerShell Script Block
Description
The following analytic utilizes PowerShell Script Block Logging (EventCode=4104) to identify the execution of the Invoke-WmiMethod
commandlet with arguments utilized to start a process on a remote endpoint by abusing WMI. Red Teams and adversaries alike may abuse WMI and this commandlet for lateral movement and remote code execution.
- Type: TTP
-
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2022-11-15
- Author: Mauricio Velazco, Splunk
- ID: 2a048c14-4634-11ec-a618-3e22fbd008af
Annotations
Kill Chain Phase
- Exploitation
NIST
CIS20
CVE
Search
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`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`
Macros
The SPL above uses the following Macros:
remote_process_instantiation_via_wmi_and_powershell_script_block_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Required fields
List of fields required to use this analytic.
- _time
- EventCode
- Message
- ComputerName
- User
How To Implement
To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup instructions can be found https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.
Known False Positives
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.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
63.0 | 90 | 70 | A process was started on a remote endpoint from $ComputerName by abusing WMI using PowerShell.exe |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
- https://attack.mitre.org/techniques/T1047/
- https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.management/invoke-wmimethod?view=powershell-5.1
Test Dataset
Replay any dataset to Splunk Enterprise by using our replay.py
tool or the UI.
Alternatively you can replay a dataset into a Splunk Attack Range
source | version: 2