[질문] 해킹 이 맞는지 알고 싶습니다.. ㅡㅡ;

Mar 27 09:56:51 files sshd(pam_unix)[28999]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=yahoobb219018248067.bbtec.net  user=root
Mar 27 09:56:56 files sshd(pam_unix)[29005]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=yahoobb219018248067.bbtec.net  user=root
Mar 27 09:57:02 files sshd(pam_unix)[29008]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=yahoobb219018248067.bbtec.net  user=root
Mar 27 09:57:08 files sshd(pam_unix)[29025]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=yahoobb219018248067.bbtec.net  user=root
Mar 27 09:57:14 files sshd(pam_unix)[29028]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=yahoobb219018248067.bbtec.net  user=root
Mar 27 09:57:19 files unix_chkpwd[29048]: check pass; user unknown
Mar 27 09:57:19 files sshd(pam_unix)[29046]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=yahoobb219018248067.bbtec.net
Mar 27 09:57:25 files sshd(pam_unix)[29049]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=yahoobb219018248067.bbtec.net  user=root
Mar 27 09:57:30 files sshd(pam_unix)[29051]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=yahoobb219018248067.bbtec.net  user=root
Mar 27 09:57:35 files sshd(pam_unix)[29053]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=yahoobb219018248067.bbtec.net  user=root
Mar 27 09:57:40 files sshd(pam_unix)[29055]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=yahoobb219018248067.bbtec.net  user=root
Mar 27 09:57:46 files sshd(pam_unix)[29057]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=yahoobb219018248067.bbtec.net  user=root
Mar 27 09:57:51 files sshd(pam_unix)[29060]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=yahoobb219018248067.bbtec.net  user=root

Mar 28 04:25:23 files unix_chkpwd[29637]: check pass; user unknown
Mar 28 04:25:23 files sshd(pam_unix)[29635]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=isis-pentium-pc.stanford.edu
Mar 28 04:25:26 files unix_chkpwd[29640]: check pass; user unknown
Mar 28 04:25:26 files sshd(pam_unix)[29638]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=isis-pentium-pc.stanford.edu
Mar 28 04:25:30 files unix_chkpwd[29644]: check pass; user unknown
Mar 28 04:25:30 files sshd(pam_unix)[29641]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=isis-pentium-pc.stanford.edu
Mar 28 04:25:34 files sshd(pam_unix)[29645]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=isis-pentium-pc.stanford.edu  user=root
Mar 28 04:25:37 files sshd(pam_unix)[29647]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=isis-pentium-pc.stanford.edu  user=root
Mar 28 04:25:42 files sshd(pam_unix)[29651]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=isis-pentium-pc.stanford.edu  user=root
Mar 28 04:25:45 files unix_chkpwd[29656]: check pass; user unknown
Mar 28 04:25:45 files sshd(pam_unix)[29654]: authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=isis-pentium-pc.stanford.edu

 

맞다면 어떻게 막아야 할까요?