Detection rules › Sigma
Suspicious PowerShell Get Current User
Detects the use of PowerShell to identify the current logged user.
Known false positives
- Legitimate PowerShell scripts
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Discovery |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| PowerShell | Event ID 4104: Creating Scriptblock text (MessageNumber of MessageTotal). |
Rule body
title: Suspicious PowerShell Get Current User
id: 4096a49c-7de4-4da0-a230-c66ccd56ea5a
status: test
description: Detects the use of PowerShell to identify the current logged user.
references:
- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1033/T1033.md#atomic-test-4---user-discovery-with-env-vars-powershell-script
- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1033/T1033.md#atomic-test-5---getcurrent-user-with-powershell-script
author: frack113
date: 2022-04-04
tags:
- attack.discovery
- attack.t1033
logsource:
product: windows
category: ps_script
definition: 'Requirements: Script Block Logging must be enabled'
detection:
selection:
ScriptBlockText|contains:
- '[System.Environment]::UserName'
- '$env:UserName'
- '[System.Security.Principal.WindowsIdentity]::GetCurrent()'
condition: selection
falsepositives:
- Legitimate PowerShell scripts
level: low
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
ScriptBlockText|contains:
- '[System.Environment]::UserName'
- '$env:UserName'
- '[System.Security.Principal.WindowsIdentity]::GetCurrent()'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
ScriptBlockText | match |
| field:"ScriptBlockText" kind:match |