title: Potential AES-encrypted PowerShell patterns in CommandLine
id: 47be590d-4a9e-4ab1-b9f6-a332709c2100
status: stable
description: |
    Detects suspicious execution of Powershell commands related to AES Encryption.
    This could be an indicator of use of Powershell to decrypt additionnal payload as observed during Emmenhtal infection.
references: https://www.orangecyberdefense.com/global/blog/cert-news/emmenhtal-a-little-known-loader-distributing-commodity-infostealers-worldwide
author: Orange Cyberdefense - Florian SIMONET
date: 2024/08/09
tags:
    - attack.execution
    - attack.defense_evasion
    - attack.t1059.001
    - attack.t1140
    - tlp.white
logsource:
    product: windows
    category: process_creation
detection:
    selection_img:
        Image|endswith:
            - '\powershell.exe'
            - '\pwsh.exe'
        OriginalFileName:
            - 'PowerShell.EXE'
            - 'pwsh.dll'
    selection_cmdline:
        CommandLine|contains|all:
            - 'System.Security.Cryptography.Aes'
            - 'CreateDecryptor'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium