Last night I had an external IP tried to access my server over SSH. The attempt was blocked as it failed to authorise in the number of times and time limit that I'd specified.

Doing a whois on the ip address comes back with:

[Querying whois.apnic.net]
% [whois.apnic.net]
% Whois data copyright terms    http://www.apnic.net/db/dbcopyright.html

% Information related to ' -'

inetnum: -
netname:        CHINANET-JS
descr:          CHINANET jiangsu province network
descr:          China Telecom
descr:          A12,Xin-Jie-Kou-Wai Street
descr:          Beijing 100088
country:        CN
admin-c:        CH93-AP
tech-c:         CJ186-AP
mnt-by:         APNIC-HM
mnt-lower:      MAINT-CHINANET-JS
mnt-routes:     MAINT-CHINANET-JS
remarks:        This object can only modify by APNIC hostmaster
remarks:        If you wish to modify this object details please
remarks:        send email to hostmaster@apnic.net with your
remarks:        organisation account name in the subject line.
status:         ALLOCATED PORTABLE
source:         APNIC
mnt-irt:        IRT-CHINANET-CN
changed:        hm-changed@apnic.net 20040223

irt:            IRT-CHINANET-CN
address:        No.31 ,jingrong street,beijing
address:        100032
e-mail:         anti-spam@ns.chinanet.cn.net
abuse-mailbox:  anti-spam@ns.chinanet.cn.net
admin-c:        CH93-AP
tech-c:         CH93-AP
auth:           # Filtered
mnt-by:         MAINT-CHINANET
changed:        anti-spam@ns.chinanet.cn.net 20101115
source:         APNIC

role:           CHINANET JIANGSU
address:        260 Zhongyang Road,Nanjing 210037
country:        CN
phone:          +86-25-86588231
phone:          +86-25-86588745
fax-no:         +86-25-86588104
e-mail:         ip@jsinfo.net
remarks:        send anti-spam reports to spam@jsinfo.net
remarks:        send abuse reports to abuse@jsinfo.net
remarks:        times in GMT+8
admin-c:        CH360-AP
tech-c:         CS306-AP
tech-c:         CN142-AP
nic-hdl:        CJ186-AP
remarks:        www.jsinfo.net
notify:         ip@jsinfo.net
mnt-by:         MAINT-CHINANET-JS
changed:        dns@jsinfo.net 20090831
changed:        ip@jsinfo.net 20090831
changed:        hm-changed@apnic.net 20090901
source:         APNIC
changed:        hm-changed@apnic.net 20111114

person:         Chinanet Hostmaster
nic-hdl:        CH93-AP
e-mail:         anti-spam@ns.chinanet.cn.net
address:        No.31 ,jingrong street,beijing
address:        100032
phone:          +86-10-58501724
fax-no:         +86-10-58501724
country:        CN
changed:        dingsy@cndata.com 20070416
changed:        zhengzm@gsta.com 20140227
mnt-by:         MAINT-CHINANET
source:         APNIC

I'm currently scanning my server that they tried to access but I can't see anything on first look that they changed anything. however, on my other server if I try to SSH into it I now get:

Warning: the ECDSA host key for '<snip>' differs from the key for the IP address '<snip>'
Offending key for IP in /home/<snip>/.ssh/known_hosts:14
Matching host key in /home/<snip>/.ssh/known_hosts:12
Are you sure you want to continue connecting (yes/no)?

The IP of the machine shouldn't have changed as all my servers are given static IPs allocated by their MAC addresses.

Could this be something related and if so, what is the best way of restoring my systems and stopping future attacks.

  • If you're worried about your SSH server being hacked, why open it to the outside world ? If it's properly secure, why spend time fretting about random scan by some china IP (the other white noise)? – Stephane Oct 22 '15 at 9:53
  • sorry - scanning my server – Tom Oct 22 '15 at 9:54
  • Please clarify your question: what do you want to know ? – Stephane Oct 22 '15 at 9:56
  • @Stephane I'm concerned about the ECDSA host key changing. I've currently shut down the server as this isn't something I've seen before as the IP addresses of my machines don't change. – Tom Oct 22 '15 at 9:59

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