Solved

postfix log file question

Posted on 2007-04-02
3
248 Views
Last Modified: 2013-12-15
I am running FC4 running postfix when i check the log files i get this:
Apr  2 01:11:02 mail2 su(pam_unix)[19952]: session opened for user dennis by (uid=0)
Apr  2 01:11:02 mail2 su(pam_unix)[19952]: session closed for user dennis
Apr  2 01:11:02 mail2 su(pam_unix)[19955]: session opened for user dennis by (uid=0)
Apr  2 01:11:02 mail2 su(pam_unix)[19955]: session closed for user dennis
Apr  2 01:11:02 mail2 su(pam_unix)[19958]: session opened for user dennis by (uid=0)
Apr  2 01:11:02 mail2 su(pam_unix)[19958]: session closed for user dennis
Apr  2 01:11:02 mail2 su(pam_unix)[19961]: session opened for user dennis by (uid=0)
Apr  2 01:11:02 mail2 su(pam_unix)[19961]: session closed for user dennis
Apr  2 01:11:02 mail2 su(pam_unix)[19964]: session opened for user dennis by (uid=0)
Apr  2 01:11:02 mail2 su(pam_unix)[19964]: session closed for user dennis
Apr  2 01:39:02 mail2 su(pam_unix)[20083]: session opened for user paul by (uid=0)
Apr  2 01:39:02 mail2 su(pam_unix)[20083]: session closed for user paul
Apr  2 01:39:02 mail2 su(pam_unix)[20086]: session opened for user paul by (uid=0)
Apr  2 01:39:02 mail2 su(pam_unix)[20086]: session closed for user paul
Apr  2 01:39:02 mail2 su(pam_unix)[20089]: session opened for user paul by (uid=0)
Apr  2 01:39:02 mail2 su(pam_unix)[20089]: session closed for user paul
Apr  2 01:39:02 mail2 su(pam_unix)[20092]: session opened for user paul by (uid=0)
Apr  2 01:39:02 mail2 su(pam_unix)[20092]: session closed for user paul
Apr  2 01:39:02 mail2 su(pam_unix)[20095]: session opened for user paul by (uid=0)
Apr  2 01:39:02 mail2 su(pam_unix)[20095]: session closed for user paul
Apr  2 03:44:01 mail2 su(pam_unix)[20622]: session opened for user billy by (uid=0)
Apr  2 03:44:01 mail2 su(pam_unix)[20622]: session closed for user billy
Apr  2 03:44:01 mail2 su(pam_unix)[20625]: session opened for user billyt by (uid=0)
Apr  2 03:44:02 mail2 su(pam_unix)[20625]: session closed for user billy
Apr  2 03:44:02 mail2 su(pam_unix)[20628]: session opened for user billy by (uid=0)
Apr  2 03:44:02 mail2 su(pam_unix)[20628]: session closed for user billy
Apr  2 03:44:02 mail2 su(pam_unix)[20631]: session opened for user billy by (uid=0)
Apr  2 03:44:02 mail2 su(pam_unix)[20631]: session closed for user billy
Apr  2 03:44:02 mail2 su(pam_unix)[20634]: session opened for user billy by (uid=0)
Apr  2 03:44:02 mail2 su(pam_unix)[20634]: session closed for user billy
Apr  2 03:44:02 mail2 su(pam_unix)[20637]: session opened for user billy by (uid=0)
Apr  2 03:44:02 mail2 su(pam_unix)[20637]: session closed for user billy

is this just postfix cycling thru the users?  

also i was wondering about creating a new root account named dennis  and then disabling the root account how do i do that?
0
Comment
Question by:knightdogs
  • 2
3 Comments
 
LVL 27

Accepted Solution

by:
Nopius earned 500 total points
Comment Utility
> is this just postfix cycling thru the users?  
No. These logs come from 'su' command executed by root to become different users: 'billy', 'paul' and 'dennis'. Why it was executed - I don't know.

> also i was wondering about creating a new root account named dennis  and then disabling the root account how do i do that?
Do you mean you need to change user name 'root' to 'denis'?
I don't recommend but it's the simplest way to do so: edit files '/etc/passwd' and /etc/shadow and change user name 'root' to 'denis'. But most system scripts that rely on username 'root' for superuser will fail.
Another approach is to use selinux, but it's too complex and it works only for FC5 and above.
Third possible way - is also to change /etc/passwd but for user 'denis' change uid and gid fields to 0, he become your second root user. Also not recommended.
0
 

Author Comment

by:knightdogs
Comment Utility
I am sorry for not being more clear.  i ran rkhunter and it said that root can be logged in to and that was a secrutiy concern.  i thought if i created another account like root, named dennis, and then disabled root that would fix it.  i saw a site 2 weeks ago that got hacked and it showed root uid 0   bla  bla  bla  and i figured that the hacker finally guessed roots password and took over so if i removed roots account i would slow them down, am i wrong?
0
 
LVL 27

Expert Comment

by:Nopius
Comment Utility
knightdogs, thanks for points.

> figured that the hacker finally guessed roots password and took over so if i removed roots account i would slow them down, am i wrong?
You are wrong. System becomes unmanageble without root account.

Disallowing root to perform _remote_ login be done in /etc/ssh/sshd_config, with option 'PermitRootLogin No'. However really good security measure to prevent password guessing is a strong enouth root password (with, suppose, 10 randomly generated characters, not a dictionary word, with catipal/small letters and with digits).

Disallowing root FTP login is also possible, depends on your system, how to do it.
Disallowing any protocol (ftp, telnet, pop3 without apop/tls) with cleartext password is also a good preventive measure.
0

Featured Post

How your wiki can always stay up-to-date

Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
- Increase transparency
- Onboard new hires faster
- Access from mobile/offline

Join & Write a Comment

Healthcare organizations in the United States must adhere to the guidance of both the HIPAA (Health Insurance Portability and Accountability Act) and HITECH (Health Information Technology for Economic and Clinical Health Act) for securing and protec…
Password hashing is better than message digests or encryption, and you should be using it instead of message digests or encryption.  Find out why and how in this article, which supplements the original article on PHP Client Registration, Login, Logo…
Learn how to find files with the shell using the find and locate commands. Use locate to find a needle in a haystack.: With locate, check if the file still exists.: Use find to get the actual location of the file.:
This demo shows you how to set up the containerized NetScaler CPX with NetScaler Management and Analytics System in a non-routable Mesos/Marathon environment for use with Micro-Services applications.

763 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

10 Experts available now in Live!

Get 1:1 Help Now