3

I see this in my Ubuntu server's log file:

in my ssh my user is root but i see other user Disconnected like "teamspeak", what does that mean?

auth.log

Jul  3 21:39:01 vmi189193 CRON[25937]: pam_unix(cron:session): session closed for user root
Jul  3 21:40:13 vmi189193 sshd[26041]: Connection closed by 190.96.22.136 port 39351 [preauth]
Jul  3 21:41:30 vmi189193 sshd[26057]: Connection closed by 190.96.22.136 port 47828 [preauth]
Jul  3 21:42:48 vmi189193 sshd[26067]: Connection closed by 190.96.22.136 port 56306 [preauth]
Jul  3 21:44:05 vmi189193 sshd[26279]: Invalid user sammy from 82.202.219.155 port 51676
Jul  3 21:44:05 vmi189193 sshd[26279]: pam_unix(sshd:auth): check pass; user unknown
Jul  3 21:44:05 vmi189193 sshd[26279]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=82.202.219.155
Jul  3 21:44:05 vmi189193 sshd[26283]: Connection closed by 190.96.22.136 port 64785 [preauth]
Jul  3 21:44:07 vmi189193 sshd[26279]: Failed password for invalid user sammy from 82.202.219.155 port 51676 ssh2
Jul  3 21:44:07 vmi189193 sshd[26279]: Connection closed by invalid user sammy 82.202.219.155 port 51676 [preauth]
Jul  3 21:45:22 vmi189193 sshd[26628]: Connection closed by 190.96.22.136 port 17263 [preauth]
Jul  3 21:46:38 vmi189193 sshd[27097]: Connection closed by 190.96.22.136 port 25740 [preauth]
Jul  3 21:47:55 vmi189193 sshd[27643]: Connection closed by 190.96.22.136 port 34217 [preauth]
Jul  3 21:49:12 vmi189193 sshd[28029]: Connection closed by 190.96.22.136 port 42696 [preauth]
Jul  3 21:50:28 vmi189193 sshd[28693]: Connection closed by 190.96.22.136 port 51173 [preauth]
Jul  3 21:51:43 vmi189193 sshd[29239]: Connection closed by 190.96.22.136 port 59649 [preauth]
Jul  3 21:52:59 vmi189193 sshd[29678]: Connection closed by 190.96.22.136 port 12126 [preauth]
Jul  3 21:53:24 vmi189193 sshd[29877]: Invalid user vbox from 198.245.63.135 port 37988
Jul  3 21:53:24 vmi189193 sshd[29877]: pam_unix(sshd:auth): check pass; user unknown
Jul  3 21:53:24 vmi189193 sshd[29877]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=198.245.63.135
Jul  3 21:53:26 vmi189193 sshd[29877]: Failed password for invalid user vbox from 198.245.63.135 port 37988 ssh2
Jul  3 21:53:26 vmi189193 sshd[29877]: Connection closed by invalid user vbox 198.245.63.135 port 37988 [preauth]
Jul  3 21:54:17 vmi189193 sshd[30249]: Connection closed by 190.96.22.136 port 20605 [preauth]
Jul  3 21:54:33 vmi189193 sshd[30329]: Invalid user teamspeak from 128.199.139.46 port 32772
Jul  3 21:54:33 vmi189193 sshd[30329]: pam_unix(sshd:auth): check pass; user unknown
Jul  3 21:54:33 vmi189193 sshd[30329]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=128.199.139.46
Jul  3 21:54:35 vmi189193 sshd[30329]: Failed password for invalid user teamspeak from 128.199.139.46 port 32772 ssh2
Jul  3 21:54:35 vmi189193 sshd[30329]: Received disconnect from 128.199.139.46 port 32772:11: Normal Shutdown, Thank you for playing [preauth]
Jul  3 21:54:35 vmi189193 sshd[30329]: Disconnected from invalid user teamspeak 128.199.139.46 port 32772 [preauth]
Jul  3 21:55:35 vmi189193 sshd[30642]: Connection closed by 190.96.22.136 port 29083 [preauth]
Jul  3 21:56:05 vmi189193 sshd[30763]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=196.65.211.46  user=root
Jul  3 21:56:07 vmi189193 sshd[30763]: Failed password for root from 196.65.211.46 port 60656 ssh2
Jul  3 21:56:23 vmi189193 sshd[30804]: Invalid user test from 46.40.224.46 port 4627
Jul  3 21:56:23 vmi189193 sshd[30804]: pam_unix(sshd:auth): check pass; user unknown
Jul  3 21:56:23 vmi189193 sshd[30804]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=46.40.224.46
Jul  3 21:56:25 vmi189193 sshd[30804]: Failed password for invalid user test from 46.40.224.46 port 4627 ssh2
Jul  3 21:56:25 vmi189193 sshd[30804]: Received disconnect from 46.40.224.46 port 4627:11: Normal Shutdown, Thank you for playing [preauth]
Jul  3 21:56:25 vmi189193 sshd[30804]: Disconnected from invalid user test 46.40.224.46 port 4627 [preauth]closed for user root


Received disconnect from 128.199.139.46 port 32772:11: Normal Shutdown, Thank you for playing [preautI]

i didn't use this ip "128.199.139.46" Does that mean that someone logged in my SSH?

syslog :

Jul  3 21:56:33 vmi189193 systemd[30808]: Startup finished in 92ms.
Jul  3 21:56:33 vmi189193 systemd[1]: Started User Manager for UID 0.
Jul  3 21:56:55 vmi189193 systemd[1]: Stopping OpenBSD Secure Shell server...
Jul  3 21:56:55 vmi189193 systemd[1]: Stopped OpenBSD Secure Shell server.
Jul  3 21:57:07 vmi189193 systemd[1]: Stopping User Manager for UID 0...
Jul  3 21:57:07 vmi189193 systemd[30808]: Stopped target Default.
Jul  3 21:57:07 vmi189193 systemd[30808]: Stopped target Basic System.
Jul  3 21:57:07 vmi189193 systemd[30808]: Stopped target Paths.
Jul  3 21:57:07 vmi189193 systemd[30808]: Stopped target Sockets.
Jul  3 21:57:07 vmi189193 systemd[30808]: Closed GnuPG cryptographic agent and passphrase cache (access for web browsers).
Jul  3 21:57:07 vmi189193 systemd[30808]: Closed GnuPG cryptographic agent and passphrase cache (restricted).
Jul  3 21:57:07 vmi189193 systemd[30808]: Closed GnuPG cryptographic agent and passphrase cache.
Jul  3 21:57:07 vmi189193 systemd[30808]: Closed GnuPG cryptographic agent (ssh-agent emulation).
Jul  3 21:57:07 vmi189193 systemd[30808]: Closed GnuPG network certificate management daemon.
Jul  3 21:57:07 vmi189193 systemd[30808]: Reached target Shutdown.
Jul  3 21:57:07 vmi189193 systemd[30808]: Starting Exit the Session...
Jul  3 21:57:07 vmi189193 systemd[30808]: Stopped target Timers.
Jul  3 21:57:07 vmi189193 systemd[30808]: Received SIGRTMIN+24 from PID 30986 (kill).
Jul  3 21:57:07 vmi189193 systemd[1]: Stopped User Manager for UID 0.
Jul  3 21:57:07 vmi189193 systemd[1]: Removed slice User Slice of root.

apache2/error.log :

[Tue Jul 03 21:45:28.709800 2018] [:error] [pid 21250] [client 196.65.211.46:63463] script '/var/www/html/wp-login.php' not found or unable to stat
[Tue Jul 03 21:45:51.223006 2018] [:error] [pid 6860] [client 196.65.211.46:55697] script '/var/www/html/p.php' not found or unable to stat
[Tue Jul 03 21:45:55.370434 2018] [:error] [pid 17177] [client 196.65.211.46:59635] script '/var/www/html/p.php' not found or unable to stat

Looks like he tried to log in to Wordpress but i don't have it.

I don't have a lot of experience in security so is that bad or was I hacked?

I disabled ssh (systemctl stop ssh). What can i do now?

  • 1
    All those logs say that authenication failed – schroeder Jul 3 '18 at 20:31
  • thank you for edit , is that mean no one was able to log in my server right ? and i am safe coz i wanna add paypal payment system and i am worry about hacker . – max Jul 3 '18 at 20:33
  • 7
    I would not say that you are "safe". All I can see from the logs is that authentication failed. I might suggest you read up a little more on administering an Ubuntu server before processing payments. – schroeder Jul 3 '18 at 20:35
8

From your logs, there are no break ins.

It shows a lot of connection attempts, but no authentication successes. And the IP 128.199.139.46 connected but timed out before finishing the authentication.

A couple suggestions:

  1. Don't log in as root

    Use another user to login and use su or sudo afterwards.

  2. Use public key for SSH login

    It's much, much more secure than a password.

  3. Change the SSH port

    It creates another barrier to attackers and thwart most random scans.

  4. Implement a IDS/IPS

    It will block attackers that get to find the alternative SSH port and start guessing passwords.

2

ThoriumBR gave a great answer, but I felt as if I should add some details about what you are seeing here.

This activity from different IP addresses is just computers automatically scanning web-facing servers, attempting to find potential vulnerabilities to leverage. Nowadays this can essentially be treated as background noise as long as you implement what ThoriumBR suggested. I've previously set up a virtual machine on Google Compute Engine and looking in the auth log shows that my VM started being scanned pretty much as soon as it was set up (although thanks to Google Cloud having keys set up for SSH this is a non-issue for me). Several months later and nothing except myself has managed to log in.

This ServerFault question has good answers about this. fail2ban is also mentioned there, but I find that each IP is only really used once per half an hour or so which in my case isn't tripping fail2ban and banning the IP (this is probably something I need to change or I haven't configured it correctly; I'm new to running servers).

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