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The following analytic detects the modification of registry keys related to the desktop wallpaper settings. It leverages Sysmon EventCode 13 to identify changes to the "Control Panel\Desktop\Wallpaper" and "Control Panel\Desktop\WallpaperStyle" registry keys, especially when the modifying process is not explorer.exe or involves suspicious file paths like temp or public directories. This activity is significant as it can indicate ransomware behavior, such as the REVIL ransomware, which changes the wallpaper to display a ransom note. If confirmed malicious, this could signify a compromised machine and the presence of ransomware, leading to potential data encryption and extortion.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-05-28
  • Author: Teoderick Contreras, Splunk
  • ID: accb0712-c381-11eb-8e5b-acde48001122




ID Technique Tactic
T1491 Defacement Impact
Kill Chain Phase
  • Actions On Objectives
  • DE.CM
  • CIS 10
`sysmon` EventCode =13  (TargetObject IN ("*\\Control Panel\\Desktop\\Wallpaper","*\\Control Panel\\Desktop\\WallpaperStyle") AND Image != "*\\explorer.exe") OR (TargetObject IN ("*\\Control Panel\\Desktop\\Wallpaper","*\\Control Panel\\Desktop\\WallpaperStyle") AND Details IN ("*\\temp\\*", "*\\users\\public\\*")) 
| stats count min(_time) as firstTime max(_time) as lastTime by EventCode Image TargetObject Details Computer process_guid process_id user_id 
| rename Computer as dest 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `modification_of_wallpaper_filter`


The SPL above uses the following Macros:

:information_source: modification_of_wallpaper_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • EventCode
  • Image
  • TargetObject
  • Details
  • dest
  • process_guid
  • process_id
  • user_id

How To Implement

To successfully implement this search, you need to be ingesting logs with the Image, TargetObject registry key, registry Details from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.

Known False Positives

3rd party tool may used to changed the wallpaper of the machine

Associated Analytic Story


Risk Score Impact Confidence Message
54.0 60 90 Wallpaper modification on $dest$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.


Test Dataset

Replay any dataset to Splunk Enterprise by using our tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 2