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ISATAP Router Address Was Set — Sigma Rule

Sigma rule d22df9cd-2aee-4089-93c7-9dc4eae77f2c. ISATAP Router Address Was Set — Sigma Rule. Detects the configuration of a new ISATAP router on a Windows host. While ISATAP is a legitimate Microsoft technology for IPv6 transition, unexpected or unauthorized ISATAP router configurations could indicate a potential IPv6 DNS Takeover attack using tools like mitm6. In such attacks, adversaries advertise themselves as DHCPv6 servers and set malicious ISATAP routers to intercept traffic. This detection should be correlated with network baselines and known legitimate ISATAP deployments in your environment.

Rule metadata and linked tags

Author: hamid. Source status: experimental; severity: medium. Source dates: 2025-10-19 / not supplied.

{
  "product": "windows",
  "service": "system"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: f23ed55bb1413a68772e71e189df78f75b07b214570213841395439512c07b18

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: ISATAP Router Address Was Set
id: d22df9cd-2aee-4089-93c7-9dc4eae77f2c
status: experimental
description: |
    Detects the configuration of a new ISATAP router on a Windows host. While ISATAP is a legitimate Microsoft technology for IPv6 transition, unexpected or unauthorized ISATAP router configurations could indicate a potential IPv6 DNS Takeover attack using tools like mitm6.
    In such attacks, adversaries advertise themselves as DHCPv6 servers and set malicious ISATAP routers to intercept traffic.
    This detection should be correlated with network baselines and known legitimate ISATAP deployments in your environment.
references:
    - https://www.blackhillsinfosec.com/mitm6-strikes-again-the-dark-side-of-ipv6/
    - https://redfoxsec.com/blog/ipv6-dns-takeover/
    - https://www.securityhq.com/blog/malicious-isatap-tunneling-unearthed-on-windows-server/
    - https://medium.com/@ninnesoturan/detecting-ipv6-dns-takeover-a54a6a88be1f
author: hamid
date: 2025-10-19
tags:
    - attack.impact
    - attack.credential-access
    - attack.collection
    - attack.initial-access
    - attack.privilege-escalation
    - attack.execution
    - attack.t1557
    - attack.t1565.002
logsource:
    product: windows
    service: system
detection:
    selection:
        EventID: 4100
        Provider_Name: 'Microsoft-Windows-Iphlpsvc'
    filter_main_localhost:
        IsatapRouter:
            - '127.0.0.1'
            - '::1'
    filter_optional_null:
        IsatapRouter: null
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Legitimate ISATAP router configuration in enterprise environments
    - IPv6 transition projects and network infrastructure changes
    - Network administrators configuring dual-stack networking
    - Automatic ISATAP configuration in some Windows deployments
level: medium

Original YAML and metadata in JSON

False positives

  • Legitimate ISATAP router configuration in enterprise environments
  • IPv6 transition projects and network infrastructure changes
  • Network administrators configuring dual-stack networking
  • Automatic ISATAP configuration in some Windows deployments

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.