Discovery using CHCP (Windows Event Log)

id: '27700.50349'
title: Discovery using CHCP
description: 'CHCP ("Change Code Page" ) is a legitimate Windows command-line utility
  used to display or set the active console''s code page. When run without parameters,
  chcp displays the number of the active console code page, providing information
  about the environment''s locale and language. Threat actors have used been observed
  using chcp during discovery activities during intrusions involving IcedID and Conti
  ransomware. This use case detects chcp executions with no command line parameters
  and a parent process of cmd or PowerShell executed by a non-system account. -- Threat
  Actor Association: APT28 (aka. Fancy Bear, Forest Blizzard, Strontium, Tsar Team)
  -- Living Off the Land Binary and Scripts (LOLBAS) (LOLBIN)'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
  "<EventID>4688<" OR Type=Process) ("chcp" OR "chcp.com") ("pwsh.exe" OR "powershell.exe"
  OR "cmd.exe") | where match(process_name, "(?i)chcp\.com") and match(process, "(?i)chcp\s+?$")
  and match(parent_process_name, "(?i)(powershell|pwsh|cmd)\.exe") and not match(user,
  "\$$") | table _time, host, user, process, process_*, parent_process_name, parent_process_*
  | bin span=1s | stats values(*) as * by _time, host '
techniques:
- discovery:system location discovery:system language discovery
technique_id:
- T1614.001
data_category:
- Process command-line parameters
- Windows event logs
references:
- https://thedfirreport.com/2022/04/04/stolen-images-campaign-ends-in-conti-ransomware/
- https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/chcp