Installing Nessus Using Apt

Nessus is a powerful security analysis tool that can help you find vulnerabilities on your servers and within your network. Lets go ahead and install it on your debian based system by using Apt.

This will install both the client and server. To run Nessus, you have to add a user to the nessus program. Nessus will not accept commands as a regular user, so you will need to add the user using sudo. Lets go ahead and add the user:

sudo nessus-adduser Add a new nessusd user
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Login : (create a login)
Authentication (pass/cert) [pass] : (do not put anything, just hit enter)

Login password : (create a password and don't forget it)
Login password (again) : (rinse, repeat)

User rules
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nessusd has a rules system which allows you to restrict the hosts
that darknet has the right to test. For instance, you may want
him to be able to scan his own host only.

Please see the nessus-adduser(8) man page for the rules syntax

Enter the rules for this user, and hit ctrl-D once you are done :
(the user can have an empty rules set)

(hit ctr-D here without entering any rules)

Login : thenameyougave
Password : ***********
DN :
Rules : Is that ok ? (y/n) [y] y
user added.

Please note above, when you are asked about Authentication (pass/cert) [pass] just press enter, as this is not needed for our install.
Also when you are asked about rules for the specific user, press CTRL+D because this is also beyond the scope of this tutorial and will not effect the install.

By default, nessusd has not started. To manully force him to, you will need to do the following:

Nessus will work without being registered, however, it will have tons of limitations. Being that it is so easy to register, I recommend going over to their site and registering. If you do not register, you will be missing out on the valuable plugins that add so much functionality to nessus. Also, you may as well stop reading this tutorial.

Nessus Registration page - Go here and start the proccess.

After you have entered your e-mail address, the instructions on how to register will not work on Debian-based OSs.

You will receive an email from Nessus telling you how to install on Debian based systems. They are wrong. They tell you the pat is:

/opt/nessus/bin/nessus-fetch

Actually, if you used apt-get, the installation path is:

Upon registering, you should see the install update automatically with the latest plugins. However, just to be sure everything went ok, and you are fully up to date, run the following command.

sudo nessus-update-plugins

Sweeeet! Now what? Well, now its time to give nessus a try. On Ubuntu, you should now have a link to the application in your Applications-->internet folder for Nessus. Go ahead and open it up. You should immediatly see a place to log in. We need to go ahead and log in using the nessus username and password we set up durring the installation process. Keep in mind, you have to have the nessusd daemon running to log in, so if you've restarted your machine, you have to go back in and do sudo /etc/init.d/nessusd start. You could set it up to run by default, however, I do not recommend this. I would just start the daemon whenever you need to run Nessus.

If all goes well you will be prompted to accept a security certificate. After that, its time to smack one of your boxes with Nessus.

Now, there are lots of tabs here, and I encourage you to go through and look at the settings. For the purposes of this tutorial, I want you to pick another computer on your network, go over to the "target" tab. Lets put the name or IP of the computer you want to run nessus against in the target box.

Great. Now lets start the scan. Just click "start the scan" at the bottom of the window. Your output, depending on what type of machine you ran this against, will show your open ports, what they are associated with, and what security errors or flaws can be used to hack the system. This is very much like a port scan on steroids. You will notice that when you run these scans against windows boxes, you will find many more critical issues, then with a linux box. Have fun scanning machines, and try not to get into too much trouble!