Windows Diskshadow Proxy Execution

name: Windows Diskshadow Proxy Execution
id: 58adae9e-8ea3-11ec-90f6-acde48001122
version: 10
creation_date: '2022-02-17'
modification_date: '2026-05-13'
author: Lou Stella, Splunk
status: production
type: TTP
description: The following analytic detects the use of DiskShadow.exe in scripting mode, which can execute arbitrary unsigned code. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions with scripting mode flags. This activity is significant because DiskShadow.exe is typically used for legitimate backup operations, but its misuse can indicate an attempt to execute unauthorized code. If confirmed malicious, this could lead to unauthorized code execution, potentially compromising the system and allowing further malicious activities.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
search: |
    | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
    as lastTime from datamodel=Endpoint.Processes where
    (Processes.process_name=diskshadow.exe OR Processes.original_file_name=diskshadow.exe)
    Processes.process IN (*-s*, */s*)
    by Processes.action Processes.dest Processes.original_file_name
       Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
       Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
       Processes.process Processes.process_exec Processes.process_guid Processes.process_hash
       Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path
       Processes.user Processes.user_id Processes.vendor_product | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_diskshadow_proxy_execution_filter`
how_to_implement: The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives: Administrators using the DiskShadow tool in their infrastructure as a main backup tool with scripts will cause false positives that can be filtered with `windows_diskshadow_proxy_execution_filter`
references:
    - https://bohops.com/2018/03/26/diskshadow-the-return-of-vss-evasion-persistence-and-active-directory-database-extraction/
drilldown_searches:
    - name: View the detection results for - "$dest$"
      search: '%original_detection_search% | search  dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | 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: Possible Signed Binary Proxy Execution on $dest$
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Living Off The Land
asset_type: Endpoint
mitre_attack_id:
    - T1218
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/T1218/diskshadow/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit