Convert indexed Sigma rules into analyst-ready detections.

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