Protect Default Port Service From WAN - Mikrotik Script
Changing the Default Service Port used by Mikrotik such as telnet, ssh, ftp, winbox, www and api. or if it is not used, it can be turned off / disabled

notes: if using a custom port, please add your own

/ip firewall filter
add action=drop chain=input dst-port=21,22,23,8291,80,8728,8279  in-interface-list=WAN protocol=tcp
add action=drop chain=input dst-rt=21,22,23,8291,80,8728,8279 in-interface-list=WAN protocol=udp