Install Nessus Scanner on AlmaLinux 9

In this guide, you will learn to Install and Configure Nessus Scanner on AlmaLinux 9.

Nessus is a network security scanner. It utilizes plug-ins, which are separate files, to
handle the vulnerability checks. This makes it easy to install plug-ins and to see which
plug-ins are installed to make sure that you are current. Nessus uses a server-client
architecture. The main server will need to be built on a supported Unix-like operating
system. The client is available for Unix, Linux, and Windows.

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Steps To Install and Configure Nessus Scanner on AlmaLinux 9

Steps To Install and Configure Nessus Scanner on AlmaLinux 9

To complete this guide, you must log in to your server as a non-root user with sudo privileges and set up a basic firewall. To do this, you can follow our guide on Initial Server Setup with AlmaLinux 9.

Now follow the steps below.

Download Nessus for AlmaLinux 9

First, you need to update your local package index with the following command:

sudo dnf update -y

Then, you need to visit the Nessus Downloads page and download the latest installer with the following command:

sudo curl --request GET \
  --url 'https://www.tenable.com/downloads/api/v2/pages/nessus/files/Nessus-10.4.1-es9.x86_64.rpm' \
  --output 'Nessus-10.4.1-es9.x86_64.rpm'

Install Nessus on AlmaLinux 9

When your download is completed, run the following command to install the Nessus scanner on your server:

sudo rpm -ivh Nessus-10.4.1-es9.x86_64.rpm

Manage Nessus Scanner Service

At this point, you need to start and enable your Nessus service by using the following commands:

# sudo systemctl start nessusd
# sudo systemctl enable nessusd

Verify your Nessus scanner is active and running on AlmaLinux 9:

sudo systemctl status nessusd

Output
● nessusd.service - The Nessus Vulnerability Scanner
     Loaded: loaded (/usr/lib/systemd/system/nessusd.service; enabled; vendor p>
     Active: active (running) since Sun 2023-01-15 05:11:37 EST; 22s ago
   Main PID: 70963 (nessus-service)
      Tasks: 13 (limit: 23609)
     Memory: 96.6M
        CPU: 21.099s
     CGroup: /system.slice/nessusd.service
...

Configure Firewall For Nessus

Here we assumed that you have enabled firewalld. Now you need to allow Nessus port through the firewall. To do this, run the command below:

sudo firewall-cmd --zone=public --permanent --add-port 8834/tcp

Reload the firewall to apply the new rules:

sudo firewall-cmd --reload

Access Nessus Scanner Web Interface

At this point, you can access your Nessus web interface by typing your server’s IP address in your web browser followed by 8834:

https://server-ip:8834

You will see the Nessus Scanner welcome page. At this point, you need to choose how you want to deploy Nessus. Select a product to get started.

Here we choose Nessus Essentials – The free version for educators, students, and hobbyists.

Then, you need to enter your information to register and get an activation code from Nessus on AlmaLinux 9.

After that, you need to enter the Nessus activation code that you have received and click continue.

Register Nessus AlmaLinux 9 — Nessus Registration

Next, you need to create a Nessus admin user on AlmaLinux 9 and click submit.

At this point, you need to wait while Nessus prepares the files to scan your assets. When it is completed, you will see your Nessus Dashboard.

Create First Scan with Nessus on AlmaLinux 9

At this point, we want to show you how to scan your AlmaLinux system for vulnerabilities via the Nessus web dashboard.

From your Nessus dashboard, click on My Scans and click Create a new scan.

Next, select the scan templates for your new scan. Here we use the template ‘Basic Network Scan‘.

At this point, you need to enter a name for your scan, the description, the folder for storing the scan, and the target server. Then, click Save to save the new scan.

From your ‘My Scan’ page, you will see the new scan that you just created. Click the start button to start the scan.

That’s it you are done.