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Network Connection Initiated To DevTunnels Domain — Sigma Rule

Sigma rule 9501f8e6-8e3d-48fc-a8a6-1089dd5d7ef4. Network Connection Initiated To DevTunnels Domain — Sigma Rule. Detects network connections to Devtunnels domains initiated by a process on a system. Attackers can abuse that feature to establish a reverse shell or persistence on a machine.

Rule metadata and linked tags

Author: Kamran Saifullah. Source status: test; severity: medium. Source dates: 2023-11-20 / not supplied.

{
  "category": "network_connection",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 517daf610f829056fd71495070044ecf896f6ae94235a9188cdf7f02cd73a9ff

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Network Connection Initiated To DevTunnels Domain
id: 9501f8e6-8e3d-48fc-a8a6-1089dd5d7ef4
related:
    - id: 4b657234-038e-4ad5-997c-4be42340bce4 # Net Connection VsCode
      type: similar
    - id: b3e6418f-7c7a-4fad-993a-93b65027a9f1 # DNS VsCode
      type: similar
    - id: 1cb0c6ce-3d00-44fc-ab9c-6d6d577bf20b # DNS DevTunnels
      type: similar
status: test
description: |
    Detects network connections to Devtunnels domains initiated by a process on a system. Attackers can abuse that feature to establish a reverse shell or persistence on a machine.
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
author: Kamran Saifullah
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

Original YAML and metadata in JSON

False positives

  • Legitimate use of Devtunnels will also trigger this.

Source references

Connected ecosystem references

Exact source-tagged techniques

Telemetry review

Read the original logsource above, then inspect the linked detection workspaces for technique-level sensor context. No per-rule telemetry equivalence is inferred.

Pinned research references. No browser attack runner, live simulation result or validated detector is asserted. Source mappings and validation limits are preserved. ATT&CK / Atomic provenance · Detection provenance.