Remote File Download via Desktopimgdownldr Utilityedit

Identifies the desktopimgdownldr utility being used to download a remote file. An adversary may use desktopimgdownldr to download arbitrary files as an alternative to certutil.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-endpoint.events.*
  • logs-windows.*

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Command and Control

Version: 5 (version history)

Added (Elastic Stack release): 7.10.0

Last modified (Elastic Stack release): 7.13.0

Rule authors: Elastic

Rule license: Elastic License v2

Rule queryedit

process where event.type in ("start", "process_started") and
(process.name : "desktopimgdownldr.exe" or
process.pe.original_file_name == "desktopimgdownldr.exe") and
process.args : "/lockscreenurl:http*"

Threat mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 5 (7.13.0 release)
  • Updated query, changed from:

    event.category:process and event.type:(start or process_started) and
    (process.name:desktopimgdownldr.exe or
    process.pe.original_file_name:desktopimgdownldr.exe) and
    process.args:/lockscreenurl\:http*
Version 4 (7.12.0 release)
  • Formatting only
Version 3 (7.11.2 release)
  • Formatting only
Version 2 (7.11.0 release)
  • Updated query, changed from:

    event.category:process and event.type:(start or process_started) and
    (process.name:desktopimgdownldr.exe or
    process.pe.original_file_name:desktopimgdownldr.exe or
    winlog.event_data.OriginalFileName:desktopimgdownldr.exe) and
    process.args:/lockscreenurl\:http*