Suspicious Creation TXT File in User Desktop


Description

Detects creation of .txt files in user desktop folders via cmd.exe. This behavior may indicate ransomware deploying ransom notes, but can also occur during legitimate administrative tasks. Analysts should investigate for suspicious filenames (e.g., "RANSOM", "DECRYPT", "READ_ME"), bulk file creation patterns, or concurrent encryption activity to determine if this is part of a ransomware attack.

Query · sigma

selection:
  Image|endswith: \cmd.exe
  TargetFilename|contains|all:
  - \Users\
  - \Desktop\
  TargetFilename|endswith: .txt
condition: selection

Known false positives

  • Unknown
Raw source Suspicious Creation TXT File in User Desktop · Sigma
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Published by SigmaHQ/sigma ↗, licensed under Detection Rule License 1.1 ↗. Reproduced here unmodified.
title: Suspicious Creation TXT File in User Desktop
id: caf02a0a-1e1c-4552-9b48-5e070bd88d11
status: test
description: |
    Detects creation of .txt files in user desktop folders via cmd.exe. This behavior may indicate ransomware deploying ransom notes, but can also occur during legitimate administrative tasks.
    Analysts should investigate for suspicious filenames (e.g., "RANSOM", "DECRYPT", "READ_ME"), bulk file creation patterns, or concurrent encryption activity to determine if this is part of a ransomware attack.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1486/T1486.md#atomic-test-5---purelocker-ransom-note
author: frack113
date: 2021-12-26
modified: 2026-01-09
tags:
    - attack.impact
    - attack.t1486
    - detection.threat-hunting
logsource:
    product: windows
    category: file_event
detection:
    selection:
        Image|endswith: '\cmd.exe'
        TargetFilename|contains|all:
            - '\Users\'
            - '\Desktop\'
        TargetFilename|endswith: '.txt'
    condition: selection
falsepositives:
    - Unknown
level: medium

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