Console CodePage Lookup Via CHCP — Sigma Rule

Rule metadata and linked tags

Author: _pete_0, TheDFIRReport. Source status: test; severity: medium. Source dates: 2022-02-21 / 2024-03-05.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: c1302120495da507d48c470d5b34cdb5d7fba0f9cc02f59a366c29b25638e8bd

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Console CodePage Lookup Via CHCP
id: 7090adee-82e2-4269-bd59-80691e7c6338
status: test
description: Detects use of chcp to look up the system locale value as part of host discovery
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
author: _pete_0, TheDFIRReport
date: 2022-02-21
modified: 2024-03-05
tags:
    - attack.discovery
    - attack.t1614.001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\cmd.exe'
        ParentCommandLine|contains|windash:
            - ' -c '
            - ' -r '
            - ' -k '
        Image|endswith: '\chcp.com'
        CommandLine|endswith:
            - 'chcp'
            - 'chcp '
            - 'chcp  '
    condition: selection
falsepositives:
    - During Anaconda update the 'conda.exe' process will eventually execution the 'chcp' command.
    - Discord was seen using chcp to look up code pages
level: medium
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_chcp_codepage_lookup/info.yml

Original YAML and metadata in JSON

False positives

• During Anaconda update the 'conda.exe' process will eventually execution the 'chcp' command.
• Discord was seen using chcp to look up code pages

Source 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