First, make sure your system has the latest updates.
sudo apt update && sudo apt full upgrade -y
Then, register for a free account for Nessus Essentials in order to recieve your activation code. Link here. There are multiple versions to choose from, I will be using the 64-bit Debian version. After downloading the archive, browse to the location of download. Unpack and install the file with one command:
dpkg -i filename
Start Nessus by typing /bin/systemctl start nessusd.service
Now, the service is running by default on port 8834. Browse to the given location https://kali:8834
Your browser might issue a SEC_ERROR_UNKNOWN_ISSUER error because the Certification Authority is not a trusted valid certificate authority and that’s okay. More on that in the official docs.
Click on Accept the Risk and Continue.
Now, the initial set up page loads up, tick the corresponding product of your choice.
In the subsequent pages you can request an activation code if you already don’t have one and create an account by filling in your details.
Last step is to set your target’s IP address & enjoy.
