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Add new powershell rule #6061

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Add new powershell rule
norbert791 Jun 11, 2026
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Apply suggestion from @nasbench
norbert791 Jun 12, 2026
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34 changes: 34 additions & 0 deletions ...ershell/powershell_script/posh_ps_cmdlet_invocation_via_exported_commands_array_index.yml
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title: Potential Cmdlet Invocation Via ExportedCommands Array Index
id: 4ff4ad3e-9fb5-4a70-9962-d6ea58090318
status: experimental
description: |
Detects PowerShell scripts that enumerate Microsoft.PowerShell.Utility exported commands
and invoke cmdlets indirectly by array index. This can be used to evade detections
that look for explicit strings such as Invoke-RestMethod or Invoke-Expression.
references:
- https://www.linkedin.com/posts/mark-o-halloran1_clickfix-defense-evasion-tactic-today-i-ugcPost-7453463467736408064-snrp
author: Norbert Jaśniewicz (AlphaSOC)
date: 2026-06-11
tags:
- attack.execution
- attack.t1059.001
- attack.stealth
- attack.t1027.010
logsource:
product: windows
category: ps_script
definition: 'Requirements: Script Block Logging must be enabled'
detection:
selection_module_export_enum:
ScriptBlockText|contains|all:
- 'Get-Module'
- 'ListAvailable'
- 'Microsoft.PowerShell.Utility'
- 'ExportedCommands'
- 'Values'
selection_index_used:
ScriptBlockText|contains: '[*]'

@frack113 frack113 Jun 20, 2026

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Will search in all the ScriptBlockText [ any caracter ] that can be prone to FP , but with the selection_module_export_enum it should be fine, isn't it ?

@norbert791 norbert791 Jun 21, 2026

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That's the idea. selection_module_export_enum should do the heavy-lifting here. selection_index_used is just to make sure that there exist a possibility of using array index within the script. A more fine tuned rule would probably check against integer literal or variable reference, but that would require using regular expressions. I think they are too heavy for what we want to achieve here.

condition: all of selection_*
falsepositives:
- Unknown
level: medium
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