Process Initiated Network Connection To Ngrok Domain

Title: Process Initiated Network Connection To Ngrok Domain
Status: test
Description: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.
References:
  -https://ngrok.com/
  -https://ngrok.com/blog-post/new-ngrok-domains
  -https://www.virustotal.com/gui/file/cca0c1182ac114b44dc52dd2058fcd38611c20bb6b5ad84710681d38212f835a/
  -https://www.rnbo.gov.ua/files/2023_YEAR/CYBERCENTER/november/APT29%20attacks%20Embassies%20using%20CVE-2023-38831%20-%20report%20en.pdf
Author: Florian Roth (Nextron Systems)
Date: 2022-07-16
modified:2025-07-30
Tags:

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

Logsource:

• category: network_connection
• product: windows

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

  condition:selection
Falsepositives:
  -Legitimate use of the ngrok service.
Level: high