Audit Users and Access Attempts to SSH on Server – How to

Securityserverssh

I've had a few security problems with a server of mine, a few SSH users have been setting up fires aka giving problems.

I would like to:

  • Track user logins and logouts
  • Track activity of these SSH, in order to discover any malicious activity
  • Prevent users from deleting logs

I am not much of a sys admin and I am quite inexperienced in this matter, so any kind of advice would be very welcome and very helpful. 🙂

Best Answer

Since we're talking about SSH servers, I will give you command line solutions.

  • Track user logins and logouts. That's easy, the file /var/log/auth.log should have this information.

  • Track activity of those users: If they are fairly innocent, you can check the file .bash_history in their home dir. You will see a list of the commands that they executed. The problem is of course that they can delete or edit this file.

  • Prevent users from deleting logs: Users shouldn't be able to touch auth.log. In order to stop them from playing with .bash_history you need to do a couple of tricks.

  • What if the user manages to obtain root access? : You're screwed. Unless they make a mistake they will be able to hide all their footsteps.