Running Nessus 5.0 in offline update mode

You might have come across situations where there is no internet access available to your Nessus scanner and you were unable to bring it up. Most of you might run into issues while installing nessus in offline mode as it is not straight forward. Unfortunately even tenable security does not have "enough" or "complete" documentation for installing nessus in offline mode.

My guide will help you install your license without any hassles. The steps I use will work on any operating system. However, the commands and syntax are specific to Linux operating system (Backtrack 5). You can change the commands according to your operating system but the logically flow remains the same. OK here we go!

Please note this is a logical flow. So make sure you follow all these six steps in their order.

Step 1: Reset Nessus configuration on your machine

We have to reset all the configurations and settings of Nessus. This step will reset nessus instance on your machine to factory install by removing any old license or configuration information.

Stop the Nessus server using any of the following command:

/sbin/service nessusd stop
or
/etc/init.d/nessusd stop


Now let us reset the Nessus license and configuration on your local system:

Command:

cd /opt/nessus/sbin

./nessus-fix --reset

Enter "Y" when prompted for confirmation.

Step 2: Download and copy the necessary registration and plugin files.

Now we have to download the registration file (nessus-fetch.rc) to register your license offline and latest plugin updates file (all-2.0.tar.gz).

run command:

# /opt/nessus/bin/nessus-fetch --challenge 

This will produce a string called “challenge” that looks like the following:

569ccd9ac72ab3a62a3115a945ef8e710c0d73b8

Next, go to https://plugins.nessus.org/offline.php and copy and paste the “challenge” string as well as the Activation Code that you received previously into the appropriate text boxes.

This will produce a custom URL that can be used to download the latest Nessus plugin feed (all-2.0.tar.gz) along with a link to the nessus-fetch.rc file at the bottom of the screen.

Note: Save this URL because you will use it every time you update your plugins, as decribed in the next section.

Copy the nessus-fetch.rc file to the host running Nessus in the following directory:

 /opt/nessus/etc/nessus/

Not let us register the scanner in offline mode: run the following command.

cd /opt/nessus/etc/nessus

nessus-fetch --register-offline nessus-fetch.rc

You will receive a message output stating registration was successful.

Step 3: Obtain and install latest plugins

Perform this step each time you perform an offline update of your plugins.

To obtain the newest plugins, go to the URL that was provided in the previous step, download the file named “all-2.0.tar.gz” and save it in the directory /opt/nessus/sbin/. To install the plugins, perform the following command:

# /opt/nessus/sbin/nessus-update-plugins all-2.0.tar.gz 

Step 4: Create an admin user

Let us create a user which will be used to login to GUI and manager nessus.

command:

nessus-adduser

Follow the instructions and create a admin user.

Step 5: Rebuild the installed plugins

Run the following command to rebuild the plugins on your system:

#/opt/nessus/sbin/nessusd -R 

This usually takes time.... So please have some patience.

Step 6: Start the nessus server

Start your nessus server and try to login using a browser

https://127.0.0.1:8834

use the credentials you created in Step 4 and login.

Good luck!!!