Sigma rule: Process Initiated Network Connection To Ngrok Domain

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-f595f7d28d82, updated 2025-07-30T00:00:00.000Z.

Rule

Title
Process Initiated Network Connection To Ngrok Domain
Status
test
Level
high
Author
Florian Roth (Nextron Systems)
Date
2022-07-16
Modified
2025-07-30
File
rules/windows/network_connection/net_connection_win_domain_ngrok.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects an executable initiating a network connection to "ngrok" domains.
Attackers were seen using this "ngrok" in order to store their second stage payloads and malware.
While communication with such domains can be legitimate, often times is a sign of either data exfiltration by malicious actors or additional download.

Log source

product
windows
category
network_connection

Detection

selection:
    Initiated: 'true'
    DestinationHostname|endswith:
        - '.ngrok-free.app'
        - '.ngrok-free.dev'
        - '.ngrok.app'
        - '.ngrok.dev'
        - '.ngrok.io'
condition: selection

False positives (as the rule lists them)

  • Legitimate use of the ngrok service.

Tags

  • attack.exfiltration
  • attack.command-and-control
  • attack.t1567
  • attack.t1572
  • attack.t1102

MITRE ATT&CK ids this rule names

Related rules

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/network_connection/net_connection_win_domain_ngrok.yml

Sources and licences

  • SigmaHQ

    "Process Initiated Network Connection To Ngrok Domain" by Florian Roth (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/network_connection/net_connection_win_domain_ngrok.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Process Initiated Network Connection To Ngrok Domain",
entity page, dataset version ref-f595f7d28d82, updated 2025-07-30T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/18249279-932f-45e2-b37a-8925f2597670 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 18249279-932f-45e2-b37a-8925f2597670, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.