Uncommon Connection to Active Directory Web Services — Sigma Rule

Rule metadata and linked tags

Author: @kostastsale. Source status: test; severity: medium. Source dates: 2024-01-26 / not supplied.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 4ae565602de74786604f83f1a0a44872e5c99bd9785fb0ae1c105f9a84cd4f37

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: Uncommon Connection to Active Directory Web Services
id: b3ad3c0f-c949-47a1-a30e-b0491ccae876
status: test
description: |
    Detects uncommon network connections to the Active Directory Web Services (ADWS) from processes not typically associated with ADWS management.
references:
    - https://medium.com/falconforce/soaphound-tool-to-collect-active-directory-data-via-adws-165aca78288c
    - https://github.com/FalconForceTeam/FalconFriday/blob/a9219dfcfd89836f34660223f47d766982bdce46/Discovery/ADWS_Connection_from_Unexpected_Binary-Win.md
author: '@kostastsale'
date: 2024-01-26
tags:
    - attack.discovery
    - attack.t1087
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: true
        DestinationPort: 9389
    filter_main_dsac:
        Image: 'C:\Windows\system32\dsac.exe'
    filter_main_ms_monitoring_agent:
        Image: 'C:\Program Files\Microsoft Monitoring Agent\'
    filter_main_powershell:
        Image|startswith:
            - 'C:\Program Files\PowerShell\7\pwsh.exe'
            - 'C:\Program Files\PowerShell\7-preview\pwsh.ex'
            - 'C:\Windows\System32\WindowsPowerShell\'
            - 'C:\Windows\SysWOW64\WindowsPowerShell\'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - ADWS is used by a number of legitimate applications that need to interact with Active Directory. These applications should be added to the allow-listing to avoid false positives.
level: medium

Original YAML and metadata in JSON

False positives

• ADWS is used by a number of legitimate applications that need to interact with Active Directory. These applications should be added to the allow-listing to avoid false positives.

Source references

• https://medium.com/falconforce/soaphound-tool-to-collect-active-directory-data-via-adws-165aca78288c
• https://github.com/FalconForceTeam/FalconFriday/blob/a9219dfcfd89836f34660223f47d766982bdce46/Discovery/ADWS_Connection_from_Unexpected_Binary-Win.md