CVE-2023-23397 Exploitation Attempt


Description

Detects outlook initiating connection to a WebDAV or SMB share, which could be a sign of CVE-2023-23397 exploitation.

Query · sigma

selection:
  EventID:
  - 4656
  - 4663
  ProcessName|endswith: \OUTLOOK.EXE
  ObjectName|contains|all:
  - \REGISTRY\MACHINE\SYSTEM
  - Services\
  ObjectName|endswith:
  - WebClient\NetworkProvider
  - LanmanWorkstation\NetworkProvider
  AccessList|contains: '%%4416'
condition: selection

Known false positives

  • Searchprotocolhost.exe likes to query these registry keys. To avoid false postives, it's better to filter out those events before they reach the SIEM
Raw source CVE-2023-23397 Exploitation Attempt · Sigma
Esc
Published by SigmaHQ/sigma ↗, licensed under Detection Rule License 1.1 ↗. Reproduced here unmodified.
title: CVE-2023-23397 Exploitation Attempt
id: 73c59189-6a6d-4b9f-a748-8f6f9bbed75c
status: test
description: Detects outlook initiating connection to a WebDAV or SMB share, which could be a sign of CVE-2023-23397 exploitation.
author: Robert Lee @quantum_cookie
date: 2023-03-16
modified: 2023-03-22
references:
    - https://www.trustedsec.com/blog/critical-outlook-vulnerability-in-depth-technical-analysis-and-recommendations-cve-2023-23397/
tags:
    - attack.credential-access
    - attack.initial-access
    - cve.2023-23397
    - detection.emerging-threats
logsource:
    service: security
    product: windows
    definition: 'Requirements: SACLs must be enabled for "Query Value" on the registry keys used in this rule'
detection:
    selection:
        EventID:
            - 4656
            - 4663
        ProcessName|endswith: '\OUTLOOK.EXE'
        # Example: \REGISTRY\MACHINE\SYSTEM\CurrentControlSet001\Services\WebClient\NetworkProvider
        ObjectName|contains|all:
            - '\REGISTRY\MACHINE\SYSTEM'
            - 'Services\'
        ObjectName|endswith:
            - 'WebClient\NetworkProvider'
            - 'LanmanWorkstation\NetworkProvider'
        AccessList|contains: '%%4416' # "Query key value"
    condition: selection
falsepositives:
    - Searchprotocolhost.exe likes to query these registry keys. To avoid false postives, it's better to filter out those events before they reach the SIEM
level: critical

Detection rules belong to the projects that publish them and remain under their own licenses. This site indexes and links to them; it claims no rights in them.