Our popular "Security Onion Fundamentals" class will be running Tuesday February 24 through Friday February 27, 2026 in San Antonio TX. Use the following code before November 30, 2025 to get 10% off!
earlybird
For more info and to register:
https://securityonionfeb2026.eventbrite.com
We've been offering our Security Onion documentation in book form on Amazon for a few years and it's now been updated for the recently released Security Onion 2.4.180!
Thanks to Richard Bejtlich for writing the inspiring foreword!
Proceeds go to the Rural Technology Fund!
This edition has been updated for Security Onion 2.4.180 and includes a 20% discount code for our on-demand training and certification!
This book covers the following Security Onion topics:
Q&A
What is the difference between this book and the online documentation?
This book is the online documentation formatted specifically for print. It also includes an inspiring foreword by Richard Bejtlich that is not available anywhere else! Proceeds go to the Rural Technology Fund! Finally, the printed book includes a 20% discount code for our on-demand training and certification.
Who should get this book?
You should get this book if you work on airgap networks or simply want a portable reference that doesn't require an Internet connection or batteries! Also anyone who wants to donate to a worthy cause like Rural Technology Fund!
What is the difference between this edition and the previous edition?
This edition has been updated for Security Onion 2.4.180!
Where do we get it?
https://securityonion.com/book
Security Onion 2.4.180 is now available and includes several new features, updated components, and many quality of life improvements! For Security Onion Pro customers, we've improved our hypervisor feature from our last release and also added a highly requested reporting feature!
Alert on Offline Agents
Security Onion can now alert on offline agents:
Release Notes
https://docs.securityonion.net/en/2.4/release-notes.html#changes
Known Issues
For a list of known issues, please see:
https://docs.securityonion.net/en/2.4/release-notes.html#known-issues
About Security Onion
Security Onion is a free and open platform built by defenders for defenders. It includes network visibility, host visibility, intrusion detection honeypots, log management, and case management.
For network visibility, we offer signature based detection via Suricata, rich protocol metadata and file extraction using your choice of either Zeek or Suricata, full packet capture, and file analysis. For host visibility, we offer the Elastic Agent which provides data collection, live queries via osquery, and centralized management using Elastic Fleet. Intrusion detection honeypots based on OpenCanary can be added to your deployment for even more enterprise visibility. All of these logs flow into Elasticsearch and we’ve built our own user interfaces for alerts, dashboards, threat hunting, case management, and grid management.
Security Onion has been downloaded over 2 million times and is being used by security teams around the world to monitor and defend their enterprises. Our easy-to-use Setup wizard allows you to build a distributed grid for your enterprise in minutes!
Documentation
You can find our online documentation here:
https://docs.securityonion.net/en/2.4/
Documentation is always a work in progress. If you find documentation that needs to be updated, please let us know as described in the Feedback section below.
New Installations
If this is your first time installing Security Onion 2.4, then we highly recommend starting with an IMPORT installation as shown at:
https://docs.securityonion.net/en/2.4/first-time-users.html
Once you’re comfortable with your IMPORT installation, then you can move on to more advanced installations as shown at:
https://docs.securityonion.net/en/2.4/architecture.html
Existing 2.4 Installations
If you have an existing Security Onion 2.4 installation, you can update to the latest version using soup:
https://docs.securityonion.net/en/2.4/soup.html
Before updating your production deployment, we highly recommend testing the upgrade process on a test deployment that closely matches your production deployment if possible. This is especially important for releases that update components like Salt and Elastic.
2.3 EOL
As a reminder, Security Onion 2.3 reached End Of Life (EOL) on April 6, 2024:
https://blog.securityonion.net/2023/10/6-month-eol-notice-for-security-onion-23.html
Thanks
Lots of love went into this release!
Special thanks to all our folks working so hard to make this release happen!
Questions, Problems, and Feedback
If you have any questions or problems, please create a new Discussion at:
https://securityonion.net/discuss
Security Onion Pro
We recently celebrated 10 years in business by announcing Security Onion Pro:
https://blog.securityonion.net/2024/07/celebrating-10-years-of-security-onion.html
Security Onion Pro includes many enterprise features that folks have been asking for:
You can read more about these enterprise features at:
https://securityonion.com/proTraining
Need training? Start with our free Security Onion Essentials training and then take a look at some of our other official Security Onion training!
https://securityonion.net/training
Security Onion Solutions Hardware Appliances
We know Security Onion's hardware needs, and our appliances are the perfect match for the platform. Leave the hardware research, testing, and support to us, so you can focus on what's important for your organization. Not only will you have confidence that your Security Onion deployment is running on the best-suited hardware, you will also be supporting future development and maintenance of the Security Onion project!
https://securityonion.com/hardware
Cloud Installations
For new Security Onion 2 installations in the cloud, this new version will soon be available on the AWS, Azure, and GCP marketplaces!
AWS Marketplace and Documentation:
https://securityonion.net/aws/?ref=_ptnr_soc_blog_250917
https://docs.securityonion.net/en/2.4/cloud-amazon.html
Azure Marketplace and documentation:
https://securityonion.net/azure
https://docs.securityonion.net/en/2.4/cloud-azure.html
GCP Marketplace and documentation:
https://securityonion.net/google
https://docs.securityonion.net/en/2.4/cloud-google.html
Thanks to Brad Duncan for sharing this pcap from 2025-08-20 on his malware traffic analysis site! Due to issues with Google flagging a warning for the site, we're not including the actual hyperlink but it should be easy to find.
We did a quick analysis of this pcap using Security Onion 2.4.170:
https://blog.securityonion.net/2025/08/security-onion-24170-now-available.htmlIf you'd like to follow along, you can do the following:
The screenshots at the bottom of this post show some of the interesting alerts and their associated AI Summaries and Guided Analysis. Keep in mind that this is not some contrived demo, we simply downloaded a recent malware PCAP from Brad Duncan's site and imported it into Security Onion. Also keep in mind that this was just a PCAP and so there was no endpoint data. Had there been endpoint data, the results would have been even more in-depth.
Want more practice? Check out our other Quick Malware Analysis posts at:
https://blog.securityonion.net/search/label/quick%20malware%20analysis
About Security Onion
Security Onion is a versatile and scalable platform that can run on small virtual machines and can also scale up to the opposite end of the hardware spectrum to take advantage of extremely powerful server-class machines. Security Onion can also scale horizontally, growing from a standalone single-machine deployment to a full distributed deployment with tens or hundreds of machines as dictated by your enterprise visibility needs. To learn more about Security Onion, please see:
https://securityonion.net
Screenshots
Let's start with an overview of all logs generated by Security Onion:
We've been offering our Security Onion documentation in book form on Amazon for a few years and it's now been updated for the recently released Security Onion 2.4.170!
Thanks to Richard Bejtlich for writing the inspiring foreword!
Proceeds go to the Rural Technology Fund!
This edition has been updated for Security Onion 2.4.170 and includes a 20% discount code for our on-demand training and certification!
This book covers the following Security Onion topics:
Q&A
What is the difference between this book and the online documentation?
This book is the online documentation formatted specifically for print. It also includes an inspiring foreword by Richard Bejtlich that is not available anywhere else! Proceeds go to the Rural Technology Fund! Finally, the printed book includes a 20% discount code for our on-demand training and certification.
Who should get this book?
You should get this book if you work on airgap networks or simply want a portable reference that doesn't require an Internet connection or batteries! Also anyone who wants to donate to a worthy cause like Rural Technology Fund!
What is the difference between this edition and the previous edition?
This edition has been updated for Security Onion 2.4.170!
Where do we get it?
https://securityonion.com/book
Security Onion 2.4.170 is now available and includes JA4, more SOC dashboards, and updated components including Elastic 8.18.4, Suricata 7.0.11, and Zeek 7.0.9! Security Onion Pro customers will also have access to our new hypervisor feature!
JA4
This release includes JA4 support:
SOC Dashboards
This release includes several new SOC dashboards!
CEF dashboard:
Security Onion Pro Hypervisor Feature
Security Onion Pro users can create a hypervisor node that can run virtualized instances of Security Onion. If you have eligible machines with extra horsepower, you can use this feature to spin up additional Security Onion virtual machines (VMs) to take advantage of that extra power. This supports most major Security Onion node types and is especially helpful if you want to optimize your hardware's potential and expand your Elastic performance and retention. Contact your account manager to see if your hardware is supported.
Install a new node, select the DISTRIBUTED deployment option, choose Existing Deployment, and then select the Hypervisor option:
Once the base domain has been configured on the hypervisor (allowing VMs to be created), it should look like this:
Release Notes
https://docs.securityonion.net/en/2.4/release-notes.html#changes
Known Issues
For a list of known issues, please see:
https://docs.securityonion.net/en/2.4/release-notes.html#known-issues
About Security Onion
Security Onion is a free and open platform built by defenders for defenders. It includes network visibility, host visibility, intrusion detection honeypots, log management, and case management.
For network visibility, we offer signature based detection via Suricata, rich protocol metadata and file extraction using your choice of either Zeek or Suricata, full packet capture, and file analysis. For host visibility, we offer the Elastic Agent which provides data collection, live queries via osquery, and centralized management using Elastic Fleet. Intrusion detection honeypots based on OpenCanary can be added to your deployment for even more enterprise visibility. All of these logs flow into Elasticsearch and we’ve built our own user interfaces for alerts, dashboards, threat hunting, case management, and grid management.
Security Onion has been downloaded over 2 million times and is being used by security teams around the world to monitor and defend their enterprises. Our easy-to-use Setup wizard allows you to build a distributed grid for your enterprise in minutes!
Documentation
You can find our online documentation here:
https://docs.securityonion.net/en/2.4/
Documentation is always a work in progress. If you find documentation that needs to be updated, please let us know as described in the Feedback section below.
New Installations
If this is your first time installing Security Onion 2.4, then we highly recommend starting with an IMPORT installation as shown at:
https://docs.securityonion.net/en/2.4/first-time-users.html
Once you’re comfortable with your IMPORT installation, then you can move on to more advanced installations as shown at:
https://docs.securityonion.net/en/2.4/architecture.html
Existing 2.4 Installations
If you have an existing Security Onion 2.4 installation, you can update to the latest version using soup:
https://docs.securityonion.net/en/2.4/soup.html
Before updating your production deployment, we highly recommend testing the upgrade process on a test deployment that closely matches your production deployment if possible. This is especially important for releases that update components like Salt and Elastic.
2.3 EOL
As a reminder, Security Onion 2.3 reached End Of Life (EOL) on April 6, 2024:
https://blog.securityonion.net/2023/10/6-month-eol-notice-for-security-onion-23.html
Thanks
Lots of love went into this release!
Special thanks to all our folks working so hard to make this release happen!
Questions, Problems, and Feedback
If you have any questions or problems, please create a new Discussion at:
https://securityonion.net/discuss
Security Onion Pro
We recently celebrated 10 years in business by announcing Security Onion Pro:
https://blog.securityonion.net/2024/07/celebrating-10-years-of-security-onion.html
Security Onion Pro includes many enterprise features that folks have been asking for:
You can read more about these enterprise features at:
https://securityonion.com/proTraining
Need training? Start with our free Security Onion Essentials training and then take a look at some of our other official Security Onion training!
https://securityonion.net/training
Security Onion Solutions Hardware Appliances
We know Security Onion's hardware needs, and our appliances are the perfect match for the platform. Leave the hardware research, testing, and support to us, so you can focus on what's important for your organization. Not only will you have confidence that your Security Onion deployment is running on the best-suited hardware, you will also be supporting future development and maintenance of the Security Onion project!
https://securityonion.com/hardware
Cloud Installations
For new Security Onion 2 installations in the cloud, this new version will soon be available on the AWS, Azure, and GCP marketplaces!
AWS Marketplace and Documentation:
https://securityonion.net/aws/?ref=_ptnr_soc_blog_250812
https://docs.securityonion.net/en/2.4/cloud-amazon.html
Azure Marketplace and documentation:
https://securityonion.net/azure
https://docs.securityonion.net/en/2.4/cloud-azure.html
GCP Marketplace and documentation:
https://securityonion.net/google
https://docs.securityonion.net/en/2.4/cloud-google.html
Screenshot Tour
If you want the quickest and easiest way to try out Security Onion 2.4, just follow the screenshots below to install an Import node. This can be done in a minimal VM with only 4GB RAM! For more information, please see:
https://docs.securityonion.net/en/2.4/first-time-users.html
