Detection rules › Sigma
PowerShell Downgrade Attack - PowerShell
Detects PowerShell downgrade attack by comparing the host versions with the actually used engine version 2.0
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1059.001 Command and Scripting Interpreter: PowerShell |
Event coverage
| Provider | Event |
|---|---|
| PowerShell | Event ID 400 |
Rule body yaml
title: PowerShell Downgrade Attack - PowerShell
id: 6331d09b-4785-4c13-980f-f96661356249
status: test
description: Detects PowerShell downgrade attack by comparing the host versions with the actually used engine version 2.0
references:
- http://www.leeholmes.com/blog/2017/03/17/detecting-and-preventing-powershell-downgrade-attacks/
author: Florian Roth (Nextron Systems), Lee Holmes (idea), Harish Segar (improvements)
date: 2017-03-22
modified: 2023-10-27
tags:
- attack.execution
- attack.t1059.001
logsource:
product: windows
category: ps_classic_start
detection:
selection:
Data|contains: 'EngineVersion=2.'
filter_main:
Data|contains: 'HostVersion=2.'
condition: selection and not filter_main
falsepositives:
- Unknown
level: medium
Stages and Predicates
Stage 0: condition
selection and not filter_mainStage 1: selection
selection:
Data|contains: 'EngineVersion=2.'
Stage 2: not filter_main
filter_main:
Data|contains: 'HostVersion=2.'
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
Data | match | HostVersion=2. |
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.
| Field | Kind | Values |
|---|---|---|
Data | match |
|