Windows Process Creation: Suspicious cmd.exe Launch with Encoded PowerShell from Cleo Suite

title: "Windows Process Creation: Suspicious cmd.exe Launch with Encoded PowerShell from Cleo Suite"
id: e15f0b57-6e37-45a6-a681-9c8af9f2c05c
status: experimental
description: This rule flags an exploitation attempt pattern where cmd.exe is spawned and the command line contains PowerShell with encoded/EncodedCommand and .Download indicators. It specifically looks for cmd.exe being launched by javaw.exe processes associated with Cleo-related parent command lines (Harmony, lexicom, VersaLex, VLTrader). The behavior matters because attackers may use encoded PowerShell to evade inspection while downloading and executing payloads. Detection relies on Windows process creation telemetry capturing parent image, parent command line, child image, and command line.
references:
  - https://www.huntress.com/blog/threat-advisory-oh-no-cleo-cleo-software-actively-being-exploited-in-the-wild
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2024/Exploits/CVE-2024-50623/proc_creation_win_exploit_cve_2024_50623_cleo.yml
author: Tanner Filip, Austin Worline, Chad Hudson, Matt Anderson, Huntrule Team
date: 2024-12-09
tags:
  - attack.initial-access
  - attack.execution
  - attack.t1190
  - cve.2024-50623
  - detection.emerging-threats
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    ParentImage|endswith: \javaw.exe
    ParentCommandLine|contains:
      - Harmony
      - lexicom
      - VersaLex
      - VLTrader
    Image|endswith: \cmd.exe
    CommandLine|contains:
      - powershell
      - " -enc "
      - " -EncodedCommand"
      - .Download
  condition: selection
falsepositives:
  - Unlikely
level: high
license: DRL-1.1
related:
  - id: f007b877-02e3-45b7-8501-1b78c2864029
    type: derived