Brian Fahrlander wrote:
I just got a notice from LogWatch with the dire warning "POSSIBLE
BREAKIN ATTEMPT!". Quite a lot of them, too. I'm already disabling the
root login and have /etc/hosts.allow turning away 'unknown' addresses.
(This version uses that, right? It's unmodified...)
The typical entry looks like this:
Oct 13 06:33:14 fahrlander sshd[13361]: warning: /etc/hosts.allow, line 6: can't verify hostname: getaddrinfo(170.67-19-122.reverse.theplanet.com, AF_INET) failed
Oct 13 06:33:14 fahrlander sshd[13361]: Did not receive identification string from 67.19.122.170
Oct 13 06:53:08 fahrlander sshd[13468]: warning: /etc/hosts.allow, line 6: can't verify hostname: getaddrinfo(170.67-19-122.reverse.theplanet.com, AF_INET) failed
Oct 13 06:53:09 fahrlander sshd[13468]: reverse mapping checking getaddrinfo for 170.67-19-122.reverse.theplanet.com failed - POSSIBLE BREAKIN ATTEMPT!
Oct 13 06:53:09 fahrlander sshd[13468]: User nobody not allowed because not listed in AllowUsers
Oct 13 06:53:09 fahrlander sshd[13469]: input_userauth_request: illegal user nobody
And this site hit me 40-50 times trying various usernames, including
'root' quite a lot. Other names such as patrick, nobody, wwwrun, www,
cyrus, horde, iceuser, rolo...it doesn't look like anything that, say,
Cisco would use on their factory defaults. They also don't look like a
set of names _I_ would use, so they probably don't know _me_. Times
range from 0633-0654...
Some questions:
- Anyone else getting this?
I used to get a few attempts every day on my home box. I moved ssh to a
different port and it stopped. As already was discussed on this list, it
is not real security measure, but it helps very well against script
kiddies. I also disabled root ssh logon and defined users allowed to
log in through ssh.
