Windows desktopimgdownldr Suspicious URL and Registry Modification via Command Line

Flags desktopimgdownldr command lines indicating potential external file download or personalization registry deletion.

FreeReviewedSigma · High · v2
Product
windows
Category
process_creation
Author
Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2020-07-03
Updated
2026-07-31
title: Windows desktopimgdownldr Suspicious URL and Registry Modification via Command Line
id: 378d2c89-487e-4b45-adb9-558c9d8dff93
status: test
description: This rule flags suspicious execution of the Microsoft desktopimgdownldr utility where the command line includes a lockscreen URL parameter, excluding cases that also reference common image file extensions. It also detects desktopimgdownldr commands that attempt to delete the PersonalizationCSP registry setting, which can indicate persistence or environment manipulation. Telemetry relies on Windows process creation events and the full command line captured at execution time.
references:
  - https://labs.sentinelone.com/living-off-windows-land-a-new-native-file-downldr/
  - https://twitter.com/SBousseaden/status/1278977301745741825
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_desktopimgdownldr_susp_execution.yml
author: Florian Roth (Nextron Systems), Huntrule Team
date: 2020-07-03
modified: 2021-11-27
tags:
  - attack.command-and-control
  - attack.t1105
logsource:
  category: process_creation
  product: windows
detection:
  selection1:
    CommandLine|contains: " /lockscreenurl:"
  selection1_filter:
    CommandLine|contains:
      - .jpg
      - .jpeg
      - .png
  selection_reg:
    CommandLine|contains|all:
      - reg delete
      - \PersonalizationCSP
  condition: ( selection1 and not selection1_filter ) or selection_reg
falsepositives:
  - False positives depend on scripts and administrative tools used in the monitored environment
level: high
license: DRL-1.1
related:
  - id: bb58aa4a-b80b-415a-a2c0-2f65a4c81009
    type: derived