Execution Of Non-Existing File

Hunt Hypothesis

Checks whether the image specified in a process creation event is not a full, absolute path (caused by process ghosting or other unorthodox methods to start a process)

Detection Rule

Sigma (Original)

title: Execution Of Non-Existing File
id: 71158e3f-df67-472b-930e-7d287acaa3e1
status: test
description: Checks whether the image specified in a process creation event is not a full, absolute path (caused by process ghosting or other unorthodox methods to start a process)
references:
    - https://pentestlaboratories.com/2021/12/08/process-ghosting/
author: Max Altgelt (Nextron Systems)
date: 2021-12-09
modified: 2022-12-14
tags:
    - attack.stealth
logsource:
    category: process_creation
    product: windows
detection:
    image_absolute_path:
        Image|contains: '\'
    filter_null:
        Image: null
    filter_empty:
        Image:
            - '-'
            - ''
    filter_4688:
        - Image:
              - 'System'
              - 'Registry'
              - 'MemCompression'
              - 'vmmem'
        - CommandLine:
              - 'Registry'
              - 'MemCompression'
              - 'vmmem'
    condition: not image_absolute_path and not 1 of filter*
falsepositives:
    - Unknown
level: high

KQL (Azure Sentinel)

imProcessCreate
| where (not(TargetProcessName contains "\\")) and (not((isnull(TargetProcessName) or (TargetProcessName in~ ("-", "")) or ((TargetProcessName in~ ("System", "Registry", "MemCompression", "vmmem")) or (TargetProcessCommandLine in~ ("Registry", "MemCompression", "vmmem"))))))

Required Data Sources

False Positive Guidance

• Unknown

References

• https://pentestlaboratories.com/2021/12/08/process-ghosting/
• SigmaHQ Rule