This is certainly nothing new, it's about the oldest attack in the book. A very good password is one important thing here. Need some help picking a good password? See: swordfish a password generator
You also could shutoff ssh service to the internet. I assume that you have a good reason for accepting ssh connections from the internet so this may not be an option. Blocking that ip address is a thought, but a determined cracker will move to another ip address.
You could try contacting the owner of the ip address. But I see it seems to originate at some school in Korea...
query: 211.52.83.42
# ENGLISH
KRNIC is not a ISP but a National Internet Registry similar to APNIC.
The followings are information of the organization that is using the IPv4 address.
IPv4 Address : 211.52.83.0-211.52.83.255
Network Name : BEAHWA-WOMAN-ACADEMY
Connect ISP Name : ELIMNET
Connect Date : 20020418
Registration Date : 20031103
[ Organization Information ]
Organization ID : ORG281566
Org Name : BEAHWA-WOMAN-ACADEMY
State : KYONGGI
Address : 12 pilwun-dong jongro-gu
Zip Code : 110-044
[ Admin Contact Information]
Name : Sukjin Jang
Org Name : BEAHWA-WOMAN-ACADEMY
State : KYONGGI
Address : 12 pilwun-dong jongro-gu
Zip Code : 110-044
Phone : +82-2-399-0799
E-Mail : domain@elim.net
[ Technical Contact Information ]
Name : Sukjin Jang
Org Name : BEAHWA-WOMAN-ACADEMY
State : KYONGGI
Address : 12 pilwun-dong jongro-gu
Zip Code : 110-044
Phone : +82-2-399-799
E-Mail : domain@elim.net
So I don't know what to tell you. It's just life on the internet... :rolleyes: