Detection rules › Sigma
Suspicious CodePage Switch Via CHCP
Detects a code page switch in command line or batch scripts to a rare language
Known false positives
- Administrative activity (adjust code pages according to your organization's region)
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
| Security-Auditing | Event ID 4688: A new process has been created. |
Rule body
title: Suspicious CodePage Switch Via CHCP
id: c7942406-33dd-4377-a564-0f62db0593a3
status: test
description: Detects a code page switch in command line or batch scripts to a rare language
references:
- https://learn.microsoft.com/en-us/windows/win32/intl/code-page-identifiers
- https://twitter.com/cglyer/status/1183756892952248325
author: Florian Roth (Nextron Systems), Jonhnathan Ribeiro, oscd.community
date: 2019-10-14
modified: 2023-03-07
tags:
- attack.stealth
- attack.t1036
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith: '\chcp.com'
CommandLine|endswith:
- ' 936' # Chinese
# - ' 1256' # Arabic
- ' 1258' # Vietnamese
# - ' 855' # Russian
# - ' 866' # Russian
# - ' 864' # Arabic
condition: selection
falsepositives:
- Administrative activity (adjust code pages according to your organization's region)
level: medium
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_chcp_codepage_switch/info.yml
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
Image|endswith: '\chcp.com'
CommandLine|endswith:
- ' 936'
- ' 1258'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | ends_with |
| field:"CommandLine" kind:ends_with |
Image | ends_with |
| field:"Image" kind:ends_with value:"\chcp.com" |