Bypassing Security Controls - Command Shell

SIGMA detection rule by RedCanary, Sigma formatting by Micah Babinski · GPL-3.0

Adversaries bypass controls using the Windows Command Shell in a plethora of ways, but you can detect the one we see most often with a simple combination of process execution and a corresponding command line. Part of the RedCanary 2024 Threat Detection Report.

title: Bypassing Security Controls - Command Shell
id: 2aaf3922-0a8b-4b7b-9c10-ea552bdff707
status: experimental
description: |
    Adversaries bypass controls using the Windows Command Shell in a plethora of ways, 
    but you can detect the one we see most often with a simple combination of process 
    execution and a corresponding command line. Part of the RedCanary 2024 Threat 
    Detection Report.
references:
    - https://redcanary.com/threat-detection-report/techniques/windows-command-shell/
author: RedCanary, Sigma formatting by Micah Babinski
date: 2024/03/21
tags:
    - attack.execution
    - attack.t1059
    - attack.t1059.003
    - attack.defense_evasion
    - attack.t1202
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\cmd.exe'
        CommandLine|contains:
            - 'bypass'
            - '-exec'
    condition: selection
falsepositives:
    - Unknown
level: low

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

0d9b2480-7155-4158-ab17-b39b7fbb8bcb

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

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