Detection rules › Sigma

Potential Exploitation of RCE Vulnerability CVE-2025-33053 - Image Load

Status
experimental
Severity
high
Log source
product windows, category image_load
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects potential exploitation of remote code execution vulnerability CVE-2025-33053 by monitoring suspicious image loads from WebDAV paths. The exploit involves malicious executables from attacker-controlled WebDAV servers loading the Windows system DLLs like gdi32.dll, netapi32.dll, etc.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 7Image loaded

Rule body yaml

title: Potential Exploitation of RCE Vulnerability CVE-2025-33053 - Image Load
id: 04fc4b22-91a6-495a-879d-0144fec5ec03
related:
    - id: abe06362-a5b9-4371-8724-ebd00cd48a04
      type: similar
    - id: 9a2d8b3e-f5a1-4c68-9e21-7d9e1cf8a123
      type: similar
status: experimental
description: |
    Detects potential exploitation of remote code execution vulnerability CVE-2025-33053
    by monitoring suspicious image loads from WebDAV paths. The exploit involves malicious executables from
    attacker-controlled WebDAV servers loading the Windows system DLLs like gdi32.dll, netapi32.dll, etc.
references:
    - https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-33053
    - https://research.checkpoint.com/2025/stealth-falcon-zero-day/
author: Swachchhanda Shrawan Poudel (Nextron Systems)
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: image_load
    product: windows
detection:
    selection_img_path:
        Image|startswith: '\\\\'
        Image|contains: '\DavWWWRoot\'
    selection_img_bin:
        Image|endswith:
            - '\route.exe'
            - '\netsh.exe'
            - '\makecab.exe'
            - '\dxdiag.exe'
            - '\ipconfig.exe'
            - '\explorer.exe'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_img_path

selection_img_path:
    Image|startswith: '\\\\'
    Image|contains: '\DavWWWRoot\'

Stage 2: selection_img_bin

selection_img_bin:
    Image|endswith:
        - '\route.exe'
        - '\netsh.exe'
        - '\makecab.exe'
        - '\dxdiag.exe'
        - '\ipconfig.exe'
        - '\explorer.exe'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Imageends_with
  • \dxdiag.exe corpus 2 (sigma 2)
  • \explorer.exe corpus 14 (sigma 14)
  • \ipconfig.exe corpus 5 (sigma 5)
  • \makecab.exe corpus 5 (sigma 5)
  • \netsh.exe corpus 28 (sigma 28)
  • \route.exe corpus 3 (sigma 3)
Imagematch
  • \DavWWWRoot\ corpus 3 (sigma 3)
Imagestarts_with
  • \\\\ corpus 4 (sigma 4)