Detection rules › Sigma

Potential Suspicious Windows Feature Enabled - ProcCreation

Status
test
Severity
medium
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects usage of the built-in PowerShell cmdlet "Enable-WindowsOptionalFeature" used as a Deployment Image Servicing and Management tool. Similar to DISM.exe, this cmdlet is used to enumerate, install, uninstall, configure, and update features and packages in Windows images

Event coverage

Rule body yaml

title: Potential Suspicious Windows Feature Enabled - ProcCreation
id: c740d4cf-a1e9-41de-bb16-8a46a4f57918
related:
    - id: 55c925c1-7195-426b-a136-a9396800e29b
      type: similar
status: test
description: |
    Detects usage of the built-in PowerShell cmdlet "Enable-WindowsOptionalFeature" used as a Deployment Image Servicing and Management tool.
    Similar to DISM.exe, this cmdlet is used to enumerate, install, uninstall, configure, and update features and packages in Windows images
references:
    - https://learn.microsoft.com/en-us/powershell/module/dism/enable-windowsoptionalfeature?view=windowsserver2022-ps
    - https://learn.microsoft.com/en-us/windows/win32/projfs/enabling-windows-projected-file-system
    - https://learn.microsoft.com/en-us/windows/wsl/install-on-server
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-12-29
tags:
    - attack.stealth
logsource:
    category: process_creation
    product: windows
detection:
    selection_cmd:
        CommandLine|contains|all:
            - 'Enable-WindowsOptionalFeature'
            - '-Online'
            - '-FeatureName'
    selection_feature:
        # Add any insecure/unusual windows features that you don't use in your environment
        CommandLine|contains:
            - 'TelnetServer'
            - 'Internet-Explorer-Optional-amd64'
            - 'TFTP'
            - 'SMB1Protocol'
            - 'Client-ProjFS'
            - 'Microsoft-Windows-Subsystem-Linux'
    condition: all of selection_*
falsepositives:
    - Legitimate usage of the features listed in the rule.
level: medium

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_cmd

selection_cmd:
    CommandLine|contains|all:
        - 'Enable-WindowsOptionalFeature'
        - '-Online'
        - '-FeatureName'

Stage 2: selection_feature

selection_feature:
    # Add any insecure/unusual windows features that you don't use in your environment
    CommandLine|contains:
        - 'TelnetServer'
        - 'Internet-Explorer-Optional-amd64'
        - 'TFTP'
        - 'SMB1Protocol'
        - 'Client-ProjFS'
        - 'Microsoft-Windows-Subsystem-Linux'

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
  • -FeatureName
  • -Online
  • Client-ProjFS
  • Enable-WindowsOptionalFeature
  • Internet-Explorer-Optional-amd64
  • Microsoft-Windows-Subsystem-Linux corpus 3 (sigma 2, elastic 1)
  • SMB1Protocol
  • TFTP
  • TelnetServer