If you find a legitimate-looking copy of Windows 8.1 Pro X64 Lite PT-BR.iso , these are the typical specs you should verify:
These custom ISOs typically prioritize speed and low storage usage by removing non-essential system components. Windows 8.1 Pro X64 Lite PT-BR.iso -FREE-
I understand you're looking for a ISO. However, I must clarify a few important points before providing guidance: If you find a legitimate-looking copy of Windows 8