Hight-loaded gateway interface, maybe BotNet

I have a problem with my router, the PPPoE interface is Hight loaded with a lot of foreign traffic
2016-01-19_094401.png
How i can chek and resolve this problem?

Again and again thousands times here. Why none reads but everyone asks the same? Drop input chain udp and tcp port 53 on your pppoe interface.

Something like that
http://www.wirelessinfo.be/index.php/mikrotik/pages/dns-blocke