접속로그를 보니, 잘못된 ssh 접속 시도가 있어 차단기록이 있습니다.
우선 해제가 되었으며, 관련 점검을 해보시기 바랍니다. 

Apr 30 10:46:07 yes opensshd[1735]: Failed password for parkboo from 121.138.111.28 port 
34648 ssh2
Apr 30 10:45:57 yes opensshd[1735]: Failed password for parkboo from 121.138.111.28 port 
34648 ssh2
Apr 30 10:45:47 yes opensshd[1735]: Failed password for parkboo from 121.138.111.28 port 
34648 ssh2
Apr 30 10:45:37 yes opensshd[1735]: Failed password for parkboo from 121.138.111.28 port 
34648 ssh2
Apr 30 10:43:12 yes opensshd[32136]: Failed password for parkboo from 121.138.111.28 port 
46886 ssh2
Apr 30 10:42:22 yes opensshd[32136]: Failed password for parkboo from 121.138.111.28 port 
46886 ssh2
Apr 30 10:39:43 yes opensshd[30180]: Failed password for parkboo from 121.138.111.28 port 
30468 ssh2
Apr 30 10:39:22 yes opensshd[29527]: Failed password for parkboo from 121.134.19.220 port 
59382 ssh2
Apr 30 10:38:32 yes opensshd[29527]: Failed password for parkboo from 121.134.19.220 port 
59382 ssh2
Apr 30 10:36:31 yes opensshd[28275]: Failed password for parkboo from 121.134.19.220 port 
55232 ssh2
Apr 30 10:36:21 yes opensshd[28275]: Failed password for parkboo from 121.134.19.220 port 
55232 ssh2
Apr 30 10:35:20 yes opensshd[27155]: Failed password for parkboo from 121.134.19.220 port 
42909 ssh2
Apr 30 10:35:10 yes opensshd[27155]: Failed password for parkboo from 121.134.19.220 port 
42909 ssh2
Apr 30 10:34:19 yes opensshd[26546]: Failed password for parkboo from 121.134.19.220 port 
50742 ssh2
Apr 30 10:34:09 yes opensshd[26546]: Failed password for parkboo from 121.134.19.220 port 
50742 ssh2
Apr 30 10:33:59 yes opensshd[26546]: Failed password for parkboo from 121.134.19.220 port 
50742 ssh2
Apr 30 10:33:38 yes opensshd[25859]: Failed password for parkboo from 121.134.19.220 port 
59109 ssh2
Apr 30 10:33:28 yes opensshd[25859]: Failed password for parkboo from 121.134.19.220 port 
59109 ssh2
Apr 30 10:32:48 yes opensshd[25859]: Failed password for parkboo from 121.134.19.220 port 
59109 ssh2
Apr 30 10:32:27 yes opensshd[25147]: Failed password for parkboo from 121.134.19.220 port 
50870 ssh2


parkboo wrote..
: 안녕하세요 관리자님.
: 계정아이디:parkboo
: 
: 회사에서 parkboo.com 접속이 안되고 있습니다. 예전에도 비슷한 일이 있었던것 같은데
: 확인 부탁드립니다.
: 
: 그리고 만약 차단이 된거라면 어떤 이유로 차단이 되었는지 알려주시면 감사하겠습니다.