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splunk-security_content/detections/endpoint/linux_ngrok_reverse_proxy_usage.yml
Nasreddine Bencherchali 11c909f725 Add YAML Formatting Job (#3889)
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Co-authored-by: Bhavin Patel <bhavin.j.patel91@gmail.com>
2026-02-26 00:00:35 +05:30

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4.6 KiB
YAML

name: Linux Ngrok Reverse Proxy Usage
id: bc84d574-708c-467d-b78a-4c1e20171f97
version: 9
date: '2026-02-25'
author: Michael Haag, Splunk
status: production
type: Anomaly
description: The following analytic detects the use of Ngrok on a Linux operating system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line arguments associated with Ngrok. This activity is significant because Ngrok can be used by adversaries to establish reverse proxies, potentially bypassing network defenses. If confirmed malicious, this could allow attackers to create persistent, unauthorized access channels, facilitating data exfiltration or further exploitation of the compromised system.
data_source:
- Sysmon for Linux EventID 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.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)`
| `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
drilldown_searches:
- name: View the detection results for - "$user$" and "$dest$"
search: '%original_detection_search% | search user = "$user$" dest = "$dest$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$user$" and "$dest$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") starthoursago=168 | 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: $info_min_time$
latest_offset: $info_max_time$
rba:
message: A reverse proxy was identified spawning from $parent_process_name$ - $process_name$ on endpoint $dest$ by user $user$.
risk_objects:
- field: user
type: user
score: 50
- field: dest
type: system
score: 50
threat_objects:
- field: parent_process_name
type: parent_process_name
- field: process_name
type: process_name
tags:
analytic_story:
- Reverse Network Proxy
asset_type: Endpoint
mitre_attack_id:
- T1572
- T1090
- T1102
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
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