Remote Process Instantiation via DCOM and PowerShell Script Block

SPLUNK detection rule by Mauricio Velazco, Splunk · Apache-2.0

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.

name: Remote Process Instantiation via DCOM and PowerShell Script Block
id: fa1c3040-4680-11ec-a618-3e22fbd008af
version: 13
creation_date: '2021-11-15'
modification_date: '2026-05-13'
author: Mauricio Velazco, Splunk
status: production
type: TTP
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.
data_source:
    - Powershell Script Block Logging 4104
search: |-
    `powershell` EventCode=4104 (ScriptBlockText="*Document.Application.ShellExecute*" OR ScriptBlockText="*Document.ActiveView.ExecuteShellCommand*")
      | 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)`
      | `remote_process_instantiation_via_dcom_and_powershell_script_block_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 instructions can be found 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: 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.
references:
    - https://attack.mitre.org/techniques/T1021/003/
    - https://www.cybereason.com/blog/dcom-lateral-movement-techniques
drilldown_searches:
    - name: View the detection results for - "$Computer$"
      search: '%original_detection_search% | search  Computer = "$Computer$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$Computer$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$Computer$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: A process was started on a remote endpoint from $dest$ by abusing WMI using PowerShell.exe
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Active Directory Lateral Movement
asset_type: Endpoint
mitre_attack_id:
    - T1021.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1021.006/lateral_movement_psh/windows-powershell-xml.log
          source: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

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Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

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