saslauthd 验证，无法显示 logname= uid=0 euid=0 tty= ruser= rhost=

Question

日志里大量出现这种信息：

more  /var/log/secure

an 29 16:13:47 z1 saslauthd[3465]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:13:49 z1 saslauthd[3466]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:13:52 z1 saslauthd[3464]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:13:54 z1 saslauthd[3467]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:13:56 z1 saslauthd[3468]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:13:58 z1 saslauthd[3465]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:01 z1 saslauthd[3468]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:03 z1 saslauthd[3467]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:05 z1 saslauthd[3465]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:08 z1 saslauthd[3468]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:10 z1 saslauthd[3467]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:12 z1 saslauthd[3465]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:14 z1 saslauthd[3468]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:17 z1 saslauthd[3467]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:19 z1 saslauthd[3468]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:21 z1 saslauthd[3466]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:24 z1 saslauthd[3467]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:26 z1 saslauthd[3468]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:28 z1 saslauthd[3467]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:31 z1 saslauthd[3464]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:33 z1 saslauthd[3465]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:35 z1 saslauthd[3466]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:38 z1 saslauthd[3468]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:40 z1 saslauthd[3467]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:42 z1 saslauthd[3466]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:44 z1 saslauthd[3468]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:46 z1 saslauthd[3467]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:48 z1 saslauthd[3466]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:51 z1 saslauthd[3464]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:53 z1 saslauthd[3465]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:55 z1 saslauthd[3466]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail
Jan 29 16:14:58 z1 saslauthd[3464]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=  user=mail

Answer 1

关键是它不显示rhost=？怎么能得知rhost的信息呢

Answer 2

攻击？

Answer 3

有人在不断的尝试不同的帐号