This is something very important rules for mikrotik because sometimes you may see there are much traffic which is generated from your network using this port . So there are the ports which can be considered as Virus port .So you have to block these ports in your mikrotik .
this rules are tested and working successfully so you just have to make it copy and past in your
winbox terminal .
/ip firewall filter
add chain=forward action=drop protocol=tcp dst-port=135 comment="conficker virus block"
add chain=forward action=drop protocol=tcp dst-port=139 comment="conficker virus block"
add chain=forward action=drop protocol=tcp dst-port=5933 comment="conficker virus block"
add chain=forward action=drop protocol=tcp dst-port=5933 comment="conficker virus block"
add chain=forward action=drop protocol=udp dst-port=135 comment="conficker virus block"
add chain=forward action=drop protocol=udp dst-port=137 comment="conficker virus block"
add chain=forward action=drop protocol=udp dst-port=138 comment="conficker virus block"
add chain=forward action=drop protocol=udp dst-port=445 comment="conficker virus block"
add chain=forward action=drop protocol=tcp dst-port=445 comment="conficker virus block"
this rules are tested and working successfully so you just have to make it copy and past in your
winbox terminal .
/ip firewall filter
add chain=forward action=drop protocol=tcp dst-port=135 comment="conficker virus block"
add chain=forward action=drop protocol=tcp dst-port=139 comment="conficker virus block"
add chain=forward action=drop protocol=tcp dst-port=5933 comment="conficker virus block"
add chain=forward action=drop protocol=tcp dst-port=5933 comment="conficker virus block"
add chain=forward action=drop protocol=udp dst-port=135 comment="conficker virus block"
add chain=forward action=drop protocol=udp dst-port=137 comment="conficker virus block"
add chain=forward action=drop protocol=udp dst-port=138 comment="conficker virus block"
add chain=forward action=drop protocol=udp dst-port=445 comment="conficker virus block"
add chain=forward action=drop protocol=tcp dst-port=445 comment="conficker virus block"