Windows Information Discovery Fsutil

name: Windows Information Discovery Fsutil
id: 2181f261-93e6-4166-a5a9-47deac58feff
version: 13
creation_date: '2022-12-06'
modification_date: '2026-05-13'
author: Teoderick Contreras, Nasreddine Bencherchali, Splunk
status: production
type: Anomaly
description: |
    The following analytic identifies the execution of the Windows built-in tool FSUTIL with the "FSINFO" or "Volume" parameters, in order to discover file system and disk information.
    This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs that include command-line details.
    Monitoring this activity is significant because FSUTIL can be abused by adversaries to gather detailed information about the file system, aiding in further exploitation.
    If confirmed malicious, this activity could enable attackers to map the file system, identify valuable data, and plan subsequent actions such as privilege escalation or persistence.
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="fsutil.exe"
      OR
      Processes.original_file_name = "fsutil.exe"
    )
    (
      Processes.process = "*fsinfo*"
      OR
      (
        Processes.process = "*volume*"
        AND
        Processes.process IN ("*diskfree*", "*list*")
      )
    )
    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_information_discovery_fsutil_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: No false positives have been identified at this time.
references:
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/fsutil
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/fsutil-volume
    - https://github.com/carlospolop/PEASS-ng/tree/master/winPEAS
    - https://www.microsoft.com/en-us/security/blog/2022/10/14/new-prestige-ransomware-impacts-organizations-in-ukraine-and-poland/
    - https://www.microsoft.com/en-us/security/blog/2021/01/20/deep-dive-into-the-solorigate-second-stage-activation-from-sunburst-to-teardrop-and-raindrop/
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"
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: process $process_name$ with commandline $process$ is executed on $dest$
analytic_story:
    - Windows Post-Exploitation
    - Prestige Ransomware
asset_type: Endpoint
mitre_attack_id:
    - T1082
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/malware/winpeas/winpeas_fsutil/fsutil-fsinfo-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit