Issues Resolved by this Article

• Unable to install Nessus on a local machine

• Confusion about registration and activation steps

• Browser security warning when accessing the Nessus web interface

• Uncertainty about which account/email to use during registration

Background

Nessus is a vulnerability scanning and assessment tool developed by Tenable. It is commonly used in IT and cybersecurity environments to identify security weaknesses in systems and applications. After installation, Nessus runs a local web service that users access through a browser to configure scans and view results.

During installation, users may encounter issues related to account creation, browser security warnings, or plugin downloads. Following the correct order of steps helps prevent these problems and ensures a successful setup.

Solution

Follow the steps below to install and configure Nessus correctly.

1. Download Nessus

• Go to: https://www.tenable.com/downloads/nessus

• Select your operating system (it is usually auto-detected).

• Create a Tenable account if prompted (use your school email if required).

2. Accept the License Agreement

• Open the installer file you downloaded.

• Accept the license agreement when prompted.

3. Install Nessus

• Install Nessus using all default settings.

• Wait for the installation process to complete.

4. Access the Nessus Web Interface

[Image: Browser showing https://localhost:8834 Nessus welcome page]

• Open a browser and go to: https://localhost:8834

• If it does not open automatically, enter the address manually.

5. Bypass Browser Security Warning (if shown)

• If you see “Your connection isn’t private,” click Advanced.

• Select Continue to site (unsafe).

6. Register for Nessus Essentials

• Click Continue.

• Select Register for Nessus Essentials.

• Click Continue again.

7. Register Your Account

• Enter your name and your Ensign email address.

• Click Register.

8. Save the Activation Code

• Copy the activation code provided.

• Save it in a secure location.

• Click Continue.

9. Create a Nessus User Account

• Create a username and password.

• Click Submit

10. Download Plugins

[Image: Nessus initializing and downloading plugins progress bar]

• Nessus will begin downloading plugins automatically.

• This may take several minutes.

• Once completed, Nessus is ready for use.

Additional Notes

• Always run Nessus on systems you are authorized to scan.

• Keep Nessus updated to ensure accurate vulnerability detection.

• Plugin updates are critical for reliable scan results.

Conclusion

By following these steps in order, you can successfully install and configure Nessus with minimal issues. Proper installation ensures the tool is ready to perform vulnerability assessments in a secure and reliable manner.