Detection rules › Sigma

Always Install Elevated MSI Spawned Cmd And Powershell

Status
test
Severity
medium
Log source
product windows, category process_creation
Author
Teymur Kheirkhabarov (idea), Mangatas Tondang (rule), oscd.community
Source
github.com/SigmaHQ/sigma

Detects Windows Installer service (msiexec.exe) spawning "cmd" or "powershell"

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: Always Install Elevated MSI Spawned Cmd And Powershell
id: 1e53dd56-8d83-4eb4-a43e-b790a05510aa
status: test
description: Detects Windows Installer service (msiexec.exe) spawning "cmd" or "powershell"
references:
    - https://image.slidesharecdn.com/kheirkhabarovoffzonefinal-181117201458/95/hunting-for-privilege-escalation-in-windows-environment-50-638.jpg
author: Teymur Kheirkhabarov (idea), Mangatas Tondang (rule), oscd.community
date: 2020-10-13
modified: 2022-10-20
tags:
    - attack.privilege-escalation
    - attack.t1548.002
logsource:
    product: windows
    category: process_creation
detection:
    selection_img:
        - Image|endswith:
              - '\cmd.exe'
              - '\powershell.exe'
              - '\pwsh.exe'
        - OriginalFileName:
              - 'Cmd.Exe'
              - 'PowerShell.EXE'
              - 'pwsh.dll'
    selection_parent:
        ParentImage|contains|all:
            - '\Windows\Installer\'
            - 'msi'
        ParentImage|endswith: 'tmp'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_img

selection_img:
    - Image|endswith:
          - '\cmd.exe'
          - '\powershell.exe'
          - '\pwsh.exe'
    - OriginalFileName:
          - 'Cmd.Exe'
          - 'PowerShell.EXE'
          - 'pwsh.dll'

Stage 2: selection_parent

selection_parent:
    ParentImage|contains|all:
        - '\Windows\Installer\'
        - 'msi'
    ParentImage|endswith: 'tmp'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Imageends_with
  • \cmd.exe corpus 130 (sigma 130)
  • \powershell.exe corpus 182 (sigma 182)
  • \pwsh.exe corpus 168 (sigma 168)
OriginalFileNameeq
  • Cmd.Exe corpus 65 (sigma 43, splunk 17, elastic 5)
  • PowerShell.EXE corpus 120 (sigma 84, splunk 30, elastic 6)
  • pwsh.dll corpus 112 (sigma 79, splunk 30, elastic 3)
ParentImageends_with
  • tmp
ParentImagematch
  • \Windows\Installer\
  • msi