name: Linux Ngrok Reverse Proxy Usage
id: bc84d574-708c-467d-b78a-4c1e20171f97
version: 1
date: '2023-01-12'
author: Michael Haag, Splunk
status: production
type: Anomaly
description: The following analytic identifies the use of Ngrok being utilized on
  the Linux operating system. Unfortunately, there is no original file name for Ngrok,
  so it may be worth an additional hunt to identify any command-line arguments. The
  sign of someone using Ngrok is not malicious, however, more recently it has become
  an adversary tool.
data_source:
- Sysmon Event ID 1
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Endpoint.Processes where Processes.process_name=ngrok
  Processes.process IN ("*start*", "*--config*","*http*","*authtoken*", "*http*",
  "*tcp*") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name
  Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id
  | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
  | `linux_ngrok_reverse_proxy_usage_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: False positives may be present if Ngrok is an authorized utility.
  Filter as needed.
references:
- https://ngrok.com
- https://www.cisa.gov/uscert/sites/default/files/publications/aa22-320a_joint_csa_iranian_government-sponsored_apt_actors_compromise_federal%20network_deploy_crypto%20miner_credential_harvester.pdf
tags:
  analytic_story:
  - Reverse Network Proxy
  asset_type: Endpoint
  confidence: 100
  impact: 50
  message: A reverse proxy was identified spawning from $parent_process_name$ -  $process_name$
    on endpoint $dest$ by user $user$.
  mitre_attack_id:
  - T1572
  - T1090
  - T1102
  observable:
  - name: user
    type: User
    role:
    - Victim
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: parent_process_name
    type: Process
    role:
    - Parent Process
  - name: process_name
    type: Process
    role:
    - Child Process
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Processes.dest
  - Processes.user
  - Processes.parent_process_name
  - Processes.parent_process
  - Processes.original_file_name
  - Processes.process_name
  - Processes.process
  - Processes.process_id
  - Processes.parent_process_path
  - Processes.process_path
  - Processes.parent_process_id
  risk_score: 50
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1572/ngrok/ngrok_linux-sysmon.log
    source: Syslog:Linux-Sysmon/Operational
    sourcetype: sysmon_linux
    update_timestamp: true