Windows Network Connections to *.devtunnels.ms
Alerts on initiated Windows network connections to .devtunnels.ms hostnames, which may indicate remote access use.
- Product
- windows
- Category
- network_connection
- Author
- Kamran Saifullah (SigmaHQ), DRL 1.1
- Published
- 2023-11-20
- Updated
- 2026-07-31
ATT&CK techniques
C2 → ExfiltrationRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
Exfiltration
Impact
What it detects
This rule flags network connections initiated by a process where the destination hostname ends with .devtunnels.ms. Such connections can be abused by attackers to establish command-and-control style access, including reverse shells or persistence mechanisms via the DevTunnels infrastructure. It relies on Windows network connection telemetry with fields indicating whether the connection was initiated and the destination hostname.
Reporting behind it
- blueteamops.medium.comhttps://blueteamops.medium.com/detecting-dev-tunnels-16f0994dc3e2
- learn.microsoft.comhttps://learn.microsoft.com/en-us/azure/developer/dev-tunnels/security
- cydefops.comhttps://cydefops.com/devtunnels-unleashed
- github.comhttps://github.com/SigmaHQ/sigma/blob/master/rules/windows/network_connection/net_connection_win_domain_devtunnels.yml
Changelog
v2- v2Candidate ingested via manual entry.2026-07-31
- v1No changelog recorded for this version.2026-07-30
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
title: Windows Network Connections to *.devtunnels.ms
id: af8fa0aa-c2aa-4f57-8581-4a762a5149b6
related:
- id: 4b657234-038e-4ad5-997c-4be42340bce4
type: similar
- id: b3e6418f-7c7a-4fad-993a-93b65027a9f1
type: similar
- id: 1cb0c6ce-3d00-44fc-ab9c-6d6d577bf20b
type: similar
- id: 9501f8e6-8e3d-48fc-a8a6-1089dd5d7ef4
type: derived
status: test
description: This rule flags network connections initiated by a process where the destination hostname ends with .devtunnels.ms. Such connections can be abused by attackers to establish command-and-control style access, including reverse shells or persistence mechanisms via the DevTunnels infrastructure. It relies on Windows network connection telemetry with fields indicating whether the connection was initiated and the destination hostname.
references:
- https://blueteamops.medium.com/detecting-dev-tunnels-16f0994dc3e2
- https://learn.microsoft.com/en-us/azure/developer/dev-tunnels/security
- https://cydefops.com/devtunnels-unleashed
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/network_connection/net_connection_win_domain_devtunnels.yml
author: Kamran Saifullah, Huntrule Team
date: 2023-11-20
tags:
- attack.exfiltration
- attack.command-and-control
- attack.t1567.001
- attack.t1572
logsource:
category: network_connection
product: windows
detection:
selection:
Initiated: "true"
DestinationHostname|endswith: .devtunnels.ms
condition: selection
falsepositives:
- Legitimate use of Devtunnels will also trigger this.
level: medium
license: DRL-1.1