Windows OneDrive Share Mounted via Net

name: Windows OneDrive Share Mounted via Net
id: af1fe9eb-911c-4679-a475-a1193b12e4d1
version: 2
creation_date: '2021-09-02'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: Anomaly
description: |-
    The following analytic detects the use of net.exe or net1.exe to mount a OneDrive share as a network drive.
    This behavior may indicate an attempt to stage, access, or exfiltrate data through a cloud-hosted WebDAV path rather than a traditional file share.
    If confirmed malicious, an attacker could use the mounted share to move data outside the environment over trusted cloud infrastructure.
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

    `process_net`
    Processes.process="*use*"
    Processes.process="*https://d.docs.live.net*"

    by Processes.process Processes.vendor_product Processes.user_id Processes.process_hash
       Processes.parent_process_name Processes.parent_process_exec Processes.action
       Processes.dest Processes.process_current_directory Processes.process_path
       Processes.process_integrity_level Processes.original_file_name Processes.parent_process
       Processes.parent_process_path Processes.parent_process_guid Processes.parent_process_id
       Processes.process_guid Processes.process_id Processes.user Processes.process_name

    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_onedrive_share_mounted_via_net_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: Legitimate users may mount OneDrive shares for synchronized access or backup purposes. Monitor for unauthorized or unusual mounting activity to reduce false alerts.
drilldown_searches:
    - earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
      name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
    - name: View risk events for the last 7 days for - "$user$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") | 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: Potential OneDrive share mounted on $dest$ via $process$.
threat_objects:
    - field: parent_process_name
      type: parent_process_name
analytic_story:
    - Data Exfiltration
asset_type: Endpoint
mitre_attack_id:
    - T1567.002
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/T1567.002/snapattack/snapattack.log
          source: XmlWinEventLog:Security
          sourcetype: XmlWinEventLog
      test_type: unit