Sigma rule: CodePage Modification Via MODE.COM To Russian Language

Rule

Title

CodePage Modification Via MODE.COM To Russian Language

Status

test

Level

medium

Author

Joseliyo Sanchez, @Joseliyo_Jstnk

Date

2024-01-17

File

rules/windows/process_creation/proc_creation_win_mode_codepage_russian.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects a CodePage modification using the "mode.com" utility to Russian language.
This behavior has been used by threat actors behind Dharma ransomware.

Log source

product

windows

category

process_creation

Detection

# VT Query: behavior:"mode con cp select=1251"
# VT Query: behavior:"mode con cp select=866"
selection_img:
    - Image|endswith: '\mode.com'
    - OriginalFileName: 'MODE.COM'
selection_cli:
    CommandLine|contains|all:
        - ' con '
        - ' cp '
        - ' select='
    CommandLine|endswith:
        - '=1251' # ANSI Cyrillic; Cyrillic (Windows) - Observed ITW by Dharma ransomware
        - '=866' # OEM Russian; Cyrillic (DOS) - Observed ITW by other malware
condition: all of selection_*

False positives (as the rule lists them)

• Russian speaking people changing the CodePage

Tags

• attack.stealth
• attack.t1036

MITRE ATT&CK ids this rule names

• T1036

Related rules

• d48c5ffa-3b02-4c0f-9a9e-3c275650dd0e (derived)

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

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_mode_codepage_russian.yml