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Detection rules › Sigma

Run PowerShell Script from ADS

Status
test
Severity
high
Log source
product windows, category process_creation
Author
Sergey Soldatov, Kaspersky Lab, oscd.community
Source
github.com/SigmaHQ/sigma

Detects PowerShell script execution from Alternate Data Stream (ADS)

MITRE ATT&CK coverage

TacticTechniques
StealthT1564.004 Hide Artifacts: NTFS File Attributes

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation
Security-AuditingEvent ID 4688A new process has been created.

Rule body yaml

title: Run PowerShell Script from ADS
id: 45a594aa-1fbd-4972-a809-ff5a99dd81b8
status: test
description: Detects PowerShell script execution from Alternate Data Stream (ADS)
references:
    - https://github.com/p0shkatz/Get-ADS/blob/1c3a3562e713c254edce1995a7d9879c687c7473/Get-ADS.ps1
author: Sergey Soldatov, Kaspersky Lab, oscd.community
date: 2019-10-30
modified: 2022-07-14
tags:
    - attack.stealth
    - attack.t1564.004
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith:
            - '\powershell.exe'
            - '\pwsh.exe'
        Image|endswith:
            - '\powershell.exe'
            - '\pwsh.exe'
        CommandLine|contains|all:
            - 'Get-Content'
            - '-Stream'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    ParentImage|endswith:
        - '\powershell.exe'
        - '\pwsh.exe'
    Image|endswith:
        - '\powershell.exe'
        - '\pwsh.exe'
    CommandLine|contains|all:
        - 'Get-Content'
        - '-Stream'

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
CommandLinematch
  • -Stream
  • Get-Content corpus 2 (sigma 2)
Imageends_with
  • \powershell.exe corpus 182 (sigma 182)
  • \pwsh.exe corpus 168 (sigma 168)
ParentImageends_with
  • \powershell.exe corpus 24 (sigma 24)
  • \pwsh.exe corpus 21 (sigma 21)