Sample YARA rules: https://yaraify.abuse.ch/yarahub/
Powershell to download YARA rules : https://github.com/marcnl/powershell/blob/main/yararules_updater.ps1
YARA guide to combine multiple YARA rules: https://community.veeam.com/yara-and-script-library-67/powershell-vbr-yara-rules-updater-6429
