Detection rules › Splunk

Windows PowerShell Get CIMInstance Remote Computer

Status
production
Severity
low
Group by
Guid, Name, Opcode, Path, ScriptBlockId, ScriptBlockText, dest, process_id, signature, signature_id, user_id, vendor_product
Author
Michael Haag, Splunk
Source
github.com/splunk/security_content

The following analytic detects the use of the Get-CimInstance cmdlet with the -ComputerName parameter, indicating an attempt to retrieve information from a remote computer. It leverages PowerShell Script Block Logging to identify this specific command execution. This activity is significant as it may indicate unauthorized remote access or information gathering by an attacker. If confirmed malicious, this could allow the attacker to collect sensitive data from remote systems, potentially leading to further exploitation or lateral movement within the network.

Known false positives

  • This is meant to be a low risk RBA anomaly analytic or to be used for hunting. Enable this with a low risk score and let it generate risk in the risk index.

MITRE ATT&CK coverage

Telemetry coverage

Rule body

name: Windows PowerShell Get CIMInstance Remote Computer
id: d8c972eb-ed84-431a-8869-ca4bd83257d1
version: 11
creation_date: '2023-03-27'
modification_date: '2026-05-13'
author: Michael Haag, Splunk
status: production
type: Anomaly
description: The following analytic detects the use of the Get-CimInstance cmdlet with the -ComputerName parameter, indicating an attempt to retrieve information from a remote computer. It leverages PowerShell Script Block Logging to identify this specific command execution. This activity is significant as it may indicate unauthorized remote access or information gathering by an attacker. If confirmed malicious, this could allow the attacker to collect sensitive data from remote systems, potentially leading to further exploitation or lateral movement within the network.
data_source:
    - Powershell Script Block Logging 4104
search: |-
    `powershell` EventCode=4104 ScriptBlockText="*get-ciminstance*" AND ScriptBlockText="*computername*"
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY dest signature signature_id
           user_id vendor_product EventID
           Guid Opcode Name
           Path ProcessID ScriptBlockId
           ScriptBlockText
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `windows_powershell_get_ciminstance_remote_computer_filter`
how_to_implement: To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://help.splunk.com/en/security-offerings/splunk-user-behavior-analytics/get-data-in/5.4.1/add-other-data-to-splunk-uba/configure-powershell-logging-to-see-powershell-anomalies-in-splunk-uba.
known_false_positives: This is meant to be a low risk RBA anomaly analytic or to be used for hunting. Enable this with a low risk score and let it generate risk in the risk index.
references:
    - https://learn.microsoft.com/en-us/powershell/module/cimcmdlets/get-ciminstance?view=powershell-7.3
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: A PowerShell Cmdlet Get-CIMInstnace was ran on $dest$, attempting to connect to a remote host.
analytic_story:
    - Active Directory Lateral Movement
asset_type: Endpoint
mitre_attack_id:
    - T1059.001
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: search

`powershell` EventCode=4104 ScriptBlockText="*get-ciminstance*" AND ScriptBlockText="*computername*"

Stage 2: fillnull

| fillnull

Stage 3: stats

| stats count min(_time) as firstTime max(_time) as lastTime
    BY dest signature signature_id
       user_id vendor_product EventID
       Guid Opcode Name
       Path ProcessID ScriptBlockId
       ScriptBlockText

Stage 4: search

| `security_content_ctime(firstTime)`

Stage 5: search

| `security_content_ctime(lastTime)`

Stage 6: search

| `windows_powershell_get_ciminstance_remote_computer_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
EventCodeeq
  • 4104 corpus 269 (splunk 269)
field:"EventID" kind:eq value:"4104"
ScriptBlockTexteq
  • "*computername*"
  • "*get-ciminstance*" corpus 2 (sigma 1, splunk 1)
field:"ScriptBlockText" kind:eq