Detectionmediumtest

Suspicious CodePage Switch Via CHCP

Detects a code page switch in command line or batch scripts to a rare language

Convert In Phoenix Studio

Open this Sigma rule in the converter with the YAML preloaded and ready for backend selection.

Launch
Florian Roth (Nextron Systems), Jonhnathan Ribeiro, oscd.communityCreated Mon Oct 14Updated Tue Mar 07c7942406-33dd-4377-a564-0f62db0593a3windows
Log Source
WindowsProcess Creation
ProductWindows← raw: windows
CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic
Detection Logic1 selector
detection:
    selection:
        Image|endswith: '\chcp.com'
        CommandLine|endswith:
            - ' 936'    # Chinese
            # - ' 1256' # Arabic
            - ' 1258'   # Vietnamese
            # - ' 855'  # Russian
            # - ' 866'  # Russian
            # - ' 864'  # Arabic
    condition: selection
False Positives

Administrative activity (adjust code pages according to your organization's region)

Testing & Validation

Regression Tests

by SigmaHQ Team
Positive Detection Test1 matchevtx

Microsoft-Windows-Sysmon

Rule Metadata
Rule ID
c7942406-33dd-4377-a564-0f62db0593a3
Status
test
Level
medium
Type
Detection
Created
Mon Oct 14
Modified
Tue Mar 07
Path
rules/windows/process_creation/proc_creation_win_chcp_codepage_switch.yml
Raw Tags
attack.t1036attack.defense-evasion
View on GitHub