It's a bout 3 days that I checked my log and saw someone with russian and Egyptian IP address trying to connect to my routr OS via SSH!
what do you recommend to prevent these attakes from russian hackers?
these are shuch IP below :
41.232.77.111
80.254.99.128
213.252.95.233

see wiki

You may want to try "Address Lists" as well under Firewall.

Basically once you identify a hackers IP you add it to a Hackers list. Then a firewall rule drops anyone that is in this list.

There are many great examples written by users here that will help you protect your system: http://wiki.mikrotik.com/wiki/Firewall

merci