Windows Potential Cloudflared Tunnel Execution

name: Windows Potential Cloudflared Tunnel Execution
id: 2e29b58e-0f5a-42fc-b435-0fdce8862831
version: 2
creation_date: '2026-05-05'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: Anomaly
description: |-
    This analytic detects command-line arguments associated with the cloudflared client used to create Cloudflare tunnels.
    Cloudflared is functionally very similar to ngrok, an ingress-as-a-service tool.
    Cloudflared reaches out to the Cloudflare Edge Servers, creating an outbound connection over HTTPS(HTTP2/QUIC), where the tunnel's controller makes services or private networks accessible.
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="*tunnel*"
    (
        (
            Processes.process="*run*"
            Processes.process="*token*"
        )
        OR
        (
            Processes.process="*--url*"
            Processes.process="*localhost*"
        )
    )

    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_potential_cloudflared_tunnel_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: Some legitimate use cases include authorized DevOps or IT teams using Cloudflared for secure remote access and network management. Filter alerts based on approved usage and trusted users.
references:
    - https://www.guidepointsecurity.com/blog/tunnel-vision-cloudflared-abused-in-the-wild/
    - https://github.com/cloudflare/cloudflared
    - https://www-bleepingcomputer-com.cdn.ampproject.org/c/s/www.bleepingcomputer.com/news/security/hackers-increasingly-abuse-cloudflare-tunnels-for-stealthy-connections/amp/
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: 50
          message: Potential Cloudflared tunnel execution observed on $dest$ via $process$.
threat_objects:
    - field: parent_process_name
      type: parent_process_name
analytic_story:
    - Reverse Network Proxy
asset_type: Endpoint
mitre_attack_id:
    - T1572
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/T1572/snapattack/snapattack.log
          source: XmlWinEventLog:Security
          sourcetype: XmlWinEventLog
      test_type: unit