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Suspicious Desktopimgdownldr Target File — Sigma Rule

Sigma rule fc4f4817-0c53-4683-a4ee-b17a64bc1039. Suspicious Desktopimgdownldr Target File — Sigma Rule. Detects a suspicious Microsoft desktopimgdownldr file creation that stores a file to a suspicious location or contains a file with a suspicious extension

Rule metadata and linked tags

testhighwindowsfile_eventattack.command-and-controlattack.t1105

Author: Florian Roth (Nextron Systems). Source status: test; severity: high. Source dates: 2020-07-03 / 2022-06-02.

{
  "product": "windows",
  "category": "file_event"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 737a364c9839d5fa8e48ba934283566a86502f868df0869558f90804bdb48d9e

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Suspicious Desktopimgdownldr Target File
id: fc4f4817-0c53-4683-a4ee-b17a64bc1039
status: test
description: Detects a suspicious Microsoft desktopimgdownldr file creation that stores a file to a suspicious location or contains a file with a suspicious extension
references:
    - https://labs.sentinelone.com/living-off-windows-land-a-new-native-file-downldr/
    - https://twitter.com/SBousseaden/status/1278977301745741825
author: Florian Roth (Nextron Systems)
date: 2020-07-03
modified: 2022-06-02
tags:
    - attack.command-and-control
    - attack.t1105
logsource:
    product: windows
    category: file_event
detection:
    selection:
        Image|endswith: '\svchost.exe'
        TargetFilename|contains: '\Personalization\LockScreenImage\'
    filter1:
        TargetFilename|contains: 'C:\Windows\'
    filter2:
        TargetFilename|contains:
            - '.jpg'
            - '.jpeg'
            - '.png'
    condition: selection and not filter1 and not filter2
falsepositives:
    - False positives depend on scripts and administrative tools used in the monitored environment
level: high

Original YAML and metadata in JSON

False positives

  • False positives depend on scripts and administrative tools used in the monitored environment

Source references

Connected ecosystem references

Exact source-tagged techniques

Telemetry review

Read the original logsource above, then inspect the linked detection workspaces for technique-level sensor context. No per-rule telemetry equivalence is inferred.

Pinned research references. No browser attack runner, live simulation result or validated detector is asserted. Source mappings and validation limits are preserved. ATT&CK / Atomic provenance · Detection provenance.