PowerShell Hotfix Enumeration

Status: test
Severity: medium
Log source: category ps_script, product windows
Author: Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects call to "Win32_QuickFixEngineering" in order to enumerate installed hotfixes often used in "enum" scripts by attackers

Known false positives

Legitimate administration scripts

MITRE ATT&CK coverage

Tactic	Techniques
Discovery	No specific technique

Telemetry coverage

Provider	Record / event type
PowerShell	Event ID 4104: Creating Scriptblock text (MessageNumber of MessageTotal).

Rule body

title: PowerShell Hotfix Enumeration
id: f5d1def8-1de0-4a0e-9794-1f6f27dd605c
status: test
description: Detects call to "Win32_QuickFixEngineering" in order to enumerate installed hotfixes often used in "enum" scripts by attackers
references:
    - https://github.com/411Hall/JAWS/blob/233f142fcb1488172aa74228a666f6b3c5c48f1d/jaws-enum.ps1
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-06-21
tags:
    - attack.discovery
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection:
        ScriptBlockText|contains|all:
            - 'Win32_QuickFixEngineering'
            - 'HotFixID'
    condition: selection
falsepositives:
    - Legitimate administration scripts
level: medium

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    ScriptBlockText|contains|all:
        - 'Win32_QuickFixEngineering'
        - 'HotFixID'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`ScriptBlockText`	match	`HotFixID` `Win32_QuickFixEngineering`	`field:"ScriptBlockText" kind:match`

PowerShell Hotfix Enumeration

Known false positives

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection

Indicators

Stage 0: `condition`

Stage 1: `selection`