PowerShell spawned by mshta.exe with mixed-case obfuscation

This rule detects instances where mshta.exe acts as a parent process to initiate powershell.exe. It specifically looks for command line arguments that employ obfuscation techniques, such as character casing variations (e.g., 'POWERsHeLl'), while simultaneously excluding standard casing, combined with flags typical of non-interactive execution (e.g., -NonInteractive or /w h /c). This pattern is commonly used by adversaries to bypass security controls and execute scripts hidden from user view.