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Description

The following analytic detects the execution of PowerShell commands that initiate a process on a remote endpoint via the DCOM protocol. It leverages PowerShell Script Block Logging (EventCode=4104) to identify the use of ShellExecute and ExecuteShellCommand. This activity is significant as it may indicate lateral movement or remote code execution attempts by adversaries. If confirmed malicious, this behavior could allow attackers to execute arbitrary code on remote systems, potentially leading to further compromise and persistence within the network.

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-05-12
  • Author: Mauricio Velazco, Splunk
  • ID: fa1c3040-4680-11ec-a618-3e22fbd008af

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1021 Remote Services Lateral Movement
T1021.003 Distributed Component Object Model Lateral Movement
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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`powershell` EventCode=4104 (ScriptBlockText="*Document.Application.ShellExecute*" OR ScriptBlockText="*Document.ActiveView.ExecuteShellCommand*") 
| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer user_id 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `remote_process_instantiation_via_dcom_and_powershell_script_block_filter`

Macros

The SPL above uses the following Macros:

:information_source: remote_process_instantiation_via_dcom_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
  • ScriptBlockText
  • Computer
  • user_id

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 DCOM 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 $Computer$ by abusing WMI using PowerShell.exe

:information_source: 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

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: 3