我注意到我的Ubuntu Xenial服务器上有一些奇怪的东西。
它在默认端口上有SSH,它有fail2ban。
Fail2ban正在检测服务器上的强制尝试,并相应地logging下来:
2017-01-12 10:58:19,927 fail2ban.filter [23119]: INFO [sshd] Found xxxx 2017-01-12 11:03:27,808 fail2ban.filter [23119]: INFO [sshd] Found xxxx 2017-01-12 11:08:37,936 fail2ban.filter [23119]: INFO [sshd] Found xxxx 2017-01-12 11:13:51,538 fail2ban.filter [23119]: INFO [sshd] Found xxxx 2017-01-12 11:18:57,939 fail2ban.filter [23119]: INFO [sshd] Found xxxx 2017-01-12 11:24:10,399 fail2ban.filter [23119]: INFO [sshd] Found xxxx 2017-01-12 11:29:23,161 fail2ban.filter [23119]: INFO [sshd] Found xxxx 2017-01-12 11:34:34,064 fail2ban.filter [23119]: INFO [sshd] Found xxxx 2017-01-12 11:39:44,540 fail2ban.filter [23119]: INFO [sshd] Found xxxx
xxxx在所有情况下都是相同的IP,而这个人只是钓鱼随机用户名,如auth.log所示:
Jan 12 12:05:46 MYSERVER sshd[23579]: Invalid user journalist from xxxx Jan 12 12:05:46 MYSERVER sshd[23579]: input_userauth_request: invalid user journalist [preauth] Jan 12 12:05:46 MYSERVER sshd[23579]: Received disconnect from xxxx port 47995:11: Normal Shutdown, Thank you for playing [preauth] Jan 12 12:05:46 MYSERVER sshd[23579]: Disconnected from xxxx port 47995 [preauth]
Fail2ban看到他们,他列出他们为“find”,但不禁止。 有任何想法吗?
编辑:
cat /etc/fail2ban/jail.d/myjails.local [apache-auth] enabled = true [sshd-ddos] enabled = true [recidive] enabled = true [dovecot] enabled = true [postfix] enabled=true
其余的configuration文件保留/etc/fail2ban/jail.conf默认值,即/etc/fail2ban/jail.conf有:
[sshd] port = ssh logpath = %(sshd_log)s [sshd-ddos] # This jail corresponds to the standard configuration in Fail2ban. # The mail-whois action send a notification e-mail with a whois request # in the body. port = ssh logpath = %(sshd_log)s
我们有:
cat /etc/fail2ban/jail.d/defaults-debian.conf [sshd] enabled = true
Fail2ban似乎没有禁止任何人 – 你提供的日志不会显示超过Ubuntu xenial提供的默认限制fail2ban。
查看你的/etc/fail2ban/jail.conf ,在[DEFAULT]部分有参数findtime (默认600 秒 ,所以10分钟)和maxretry (默认5 次 ,在那个查找窗口内)。 也就是说,一小时只尝试几个密码的人不会触发它。
请注意,您不需要更改此文件(不应该,为了能够干净地升级它)。 你可以把[DEFAULT]块放到你的/etc/fail2ban/jail.d/myjails.local ,
[DEFAULT] findtime = 3600 bantime = 3600 maxretry = 4
jail.conf的开头,它实际上给出了一些关于如何和为什么的提示。