Windows Process Creation: Possible CVE-2025-33053 WebDAV RCE via utility search-order manipulation

Flags suspicious child execution from WebDAV/UNC paths initiated by iediagcmd.exe or CustomShellHost.exe, consistent with CVE-2025-33053 exploitation.

FreeReviewedSigma · High · v5
Product
windows
Category
process_creation
Author
Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2025-06-13
Updated
2026-07-31
title: "Windows Process Creation: Possible CVE-2025-33053 WebDAV RCE via utility search-order manipulation"
id: a74dc046-3f36-4aa6-adc7-7ee33c05f6b8
related:
  - id: 9a2d8b3e-f5a1-4c68-9e21-7d9e1cf8a123
    type: similar
  - id: 04fc4b22-91a6-495a-879d-0144fec5ec03
    type: similar
  - id: abe06362-a5b9-4371-8724-ebd00cd48a04
    type: derived
status: experimental
description: This rule identifies Windows process creation events consistent with potential remote code execution exploitation tied to CVE-2025-33053. It looks for iediagcmd.exe or CustomShellHost.exe launching follow-on executables (including route.exe, netsh.exe, makecab.exe, dxdiag.exe, ipconfig.exe, explorer.exe) where the current directory or image path involves attacker-controlled WebDAV locations such as \\DavWWWRoot\ or UNC paths. The behavior matters because it suggests an attacker may abuse legitimate utilities and working-directory/path resolution to run malicious binaries from a WebDAV share instead of expected system executables. Detection relies on process creation telemetry including parent image, current directory, and the child image path, with exclusions for child images under standard system directories.
references:
  - https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-33053
  - https://research.checkpoint.com/2025/stealth-falcon-zero-day/
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2025/Exploits/CVE-2025-33053/proc_creation_win_exploit_cve_2025_33053.yml
author: Swachchhanda Shrawan Poudel (Nextron Systems), Huntrule Team
date: 2025-06-13
tags:
  - attack.command-and-control
  - attack.execution
  - attack.stealth
  - attack.t1218
  - attack.lateral-movement
  - attack.t1105
  - detection.emerging-threats
  - cve.2025-33053
logsource:
  category: process_creation
  product: windows
detection:
  selection_parent:
    ParentImage:
      - C:\Program Files\internet explorer\iediagcmd.exe
      - C:\Windows\System32\CustomShellHost.exe
  selection_child_current_dir:
    - CurrentDirectory|startswith: \\\\
    - CurrentDirectory|contains: \DavWWWRoot\
    - Image|contains: \DavWWWRoot\
    - Image|startswith: \\\\
  selection_child_img:
    Image|endswith:
      - \route.exe
      - \netsh.exe
      - \makecab.exe
      - \dxdiag.exe
      - \ipconfig.exe
      - \explorer.exe
  filter_main_system:
    Image|startswith:
      - C:\Windows\System32\
      - C:\Windows\SysWOW64\
  condition: all of selection_* and not 1 of filter_main_*
falsepositives:
  - Unknown
level: high
license: DRL-1.1