Detection rules › Sigma

Execution Of Non-Existing File

Status
test
Severity
high
Log source
product windows, category process_creation
Author
Max Altgelt (Nextron Systems)
Source
github.com/SigmaHQ/sigma

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)

MITRE ATT&CK coverage

TacticTechniques
StealthNo specific technique

Event coverage

Rule body yaml

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

Stages and Predicates

Stage 0: condition

not image_absolute_path and not 1 of filter*

Stage 1: not image_absolute_path

image_absolute_path:
    Image|contains: '\'

Stage 2: not filter*

filter_null:
    Image: null
filter_empty:
    Image:
        - '-'
        - ''
filter_4688:
    - Image:
          - 'System'
          - 'Registry'
          - 'MemCompression'
          - 'vmmem'
    - CommandLine:
          - 'Registry'
          - 'MemCompression'
          - 'vmmem'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
Imagematch\
CommandLineeqMemCompression
CommandLineeqRegistry
CommandLineeqvmmem
Imageeq-
ImageeqMemCompression
ImageeqRegistry
ImageeqSystem
Imageeqvmmem
Imageis_null(no value, null check)