Windows: Detect MODE.COM Changing Code Page Settings

Detects MODE.COM executions that include code page selection parameters.

FreeReviewedSigma · Low · v5
Product
windows
Category
process_creation
Author
Nasreddine Bencherchali (Nextron Systems), Joseliyo Sanchez, @Joseliyo_Jstnk (SigmaHQ), DRL 1.1
Published
2024-01-19
Updated
2026-07-31
title: "Windows: Detect MODE.COM Changing Code Page Settings"
id: 3e0928dd-4294-4a80-a1ee-22bb3ca30076
related:
  - id: 12fbff88-16b5-4b42-9754-cd001a789fb3
    type: derived
  - id: d48c5ffa-3b02-4c0f-9a9e-3c275650dd0e
    type: derived
status: test
description: This rule flags process executions of MODE.COM where the command line includes typical parameters for changing code page and selecting a code page ("cp" and "select="). Attackers may use this to alter how text/console output is interpreted or recorded, which can affect operator visibility and downstream tooling. The detection relies on Windows process creation telemetry, matching the executable name/path and specific command-line substrings.
references:
  - https://learn.microsoft.com/en-us/windows/win32/intl/code-page-identifiers
  - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/mode
  - https://strontic.github.io/xcyclopedia/library/mode.com-59D1ED51ACB8C3D50F1306FD75F20E99.html
  - https://www.virustotal.com/gui/file/5e75ef02517afd6e8ba6462b19217dc4a5a574abb33d10eb0f2bab49d8d48c22/behavior
  - https://github.com/SigmaHQ/sigma/blob/master/rules-threat-hunting/windows/process_creation/proc_creation_win_mode_codepage_change.yml
author: Nasreddine Bencherchali (Nextron Systems), Joseliyo Sanchez, @Joseliyo_Jstnk, Huntrule Team
date: 2024-01-19
tags:
  - attack.stealth
  - attack.t1036
  - detection.threat-hunting
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    - Image|endswith: \mode.com
    - OriginalFileName: MODE.COM
  selection_cli:
    CommandLine|contains|all:
      - " con "
      - " cp "
      - " select="
  condition: all of selection_*
falsepositives:
  - Unknown
level: low
license: DRL-1.1