Because of known issues with USB being vulnerable to USB attacks and the missing option of disabling USB i created a script and scheduler to handle USB Power. USB can be disable with a power command but it has a timer so the timer needs to be reset every X seconds/minutes. The script will run on reboot to disable USB and after that run every 60 minutes to reset the usb timer. This script does not give you 100% protection neither do we take any responsibilities for any damage done to your devices by this script or any attackers.
Just log in to your MikroTik and paste the following command
/tool fetch url=https://raw.githubusercontent.com/marvin/mtik-disable-usb/master/install.rsc;
/import file-name=install.rsc"