sigmamediumHunting

Process Creation Using Sysnative Folder

Detects process creation events that use the Sysnative folder (common for CobaltStrike spawns)

MITRE ATT&CK

defense-evasionprivilege-escalation

Detection Query

selection:
  - CommandLine|contains: :\Windows\Sysnative\
  - Image|contains: :\Windows\Sysnative\
filter_main_ngen:
  Image|contains:
    - C:\Windows\Microsoft.NET\Framework64\v
    - C:\Windows\Microsoft.NET\Framework\v
    - C:\Windows\Microsoft.NET\FrameworkArm\v
    - C:\Windows\Microsoft.NET\FrameworkArm64\v
  Image|endswith: \ngen.exe
  CommandLine|contains: install
filter_optional_xampp:
  CommandLine|contains|all:
    - '"C:\Windows\sysnative\cmd.exe"'
    - \xampp\
    - \catalina_start.bat
condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*

Author

Max Altgelt (Nextron Systems)

Created

2022-08-23

Data Sources

windowsProcess Creation Events

Platforms

windows

References

https://thedfirreport.com/2021/08/29/cobalt-strike-a-defenders-guide/

Tags

attack.defense-evasionattack.privilege-escalationattack.t1055

Raw Content

title: Process Creation Using Sysnative Folder
id: 3c1b5fb0-c72f-45ba-abd1-4d4c353144ab
status: test
description: Detects process creation events that use the Sysnative folder (common for CobaltStrike spawns)
references:
    - https://thedfirreport.com/2021/08/29/cobalt-strike-a-defenders-guide/
author: Max Altgelt (Nextron Systems)
date: 2022-08-23
modified: 2025-10-08
tags:
    - attack.defense-evasion
    - attack.privilege-escalation
    - attack.t1055
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        - CommandLine|contains: ':\Windows\Sysnative\'
        - Image|contains: ':\Windows\Sysnative\'
    filter_main_ngen:
        Image|contains:
            - 'C:\Windows\Microsoft.NET\Framework64\v'
            - 'C:\Windows\Microsoft.NET\Framework\v'
            - 'C:\Windows\Microsoft.NET\FrameworkArm\v'
            - 'C:\Windows\Microsoft.NET\FrameworkArm64\v'
        Image|endswith: '\ngen.exe'
        CommandLine|contains: 'install'
    filter_optional_xampp:
        CommandLine|contains|all:
            - '"C:\Windows\sysnative\cmd.exe"'
            - '\xampp\'
            - '\catalina_start.bat'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: medium