Uncommon Windows Processes Writing .txt/.xml in AppData\Roaming\Microsoft

Flags creation of .txt/.xml files in AppData\Roaming\Microsoft by schtasks.exe, wscript.exe, or mshta.exe.

FreeReviewedSigma · High · v5
Product
windows
Category
file_event
Author
Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2023-05-15
Updated
2026-07-31
title: Uncommon Windows Processes Writing .txt/.xml in AppData\Roaming\Microsoft
id: 1875e1ae-c163-430d-ba3f-41a52fa48648
status: test
description: This rule flags file creation where the target path is within \AppData\Roaming\Microsoft\ and the created filename ends with .txt or .xml. It specifically matches creations initiated by schtasks.exe, wscript.exe, or mshta.exe, which are often used to execute or stage content from user-writable locations. The detection relies on Windows file event telemetry capturing the creating process path and the target filename/path. Such activity can indicate stealthy staging of additional payloads or configuration data in a commonly abused directory.
references:
  - https://www.ncsc.gov.uk/static-assets/documents/malware-analysis-reports/devil-bait/NCSC-MAR-Devil-Bait.pdf
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2021/Malware/Devil-Bait/file_event_win_malware_devil_bait_script_drop.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2023-05-15
tags:
  - detection.emerging-threats
  - attack.stealth
logsource:
  product: windows
  category: file_event
detection:
  selection:
    Image|endswith:
      - \schtasks.exe
      - \wscript.exe
      - \mshta.exe
    TargetFilename|contains: \AppData\Roaming\Microsoft\
    TargetFilename|endswith:
      - .txt
      - .xml
  condition: selection
falsepositives:
  - Unlikely
level: high
license: DRL-1.1
related:
  - id: 93d5f1b4-36df-45ed-8680-f66f242b8415
    type: derived