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Vol. 1 · Ed. 2026
CyberGlossary
Entry № 997

Security Onion

What is Security Onion?

Security OnionA free, open-source Linux distribution for threat hunting, network security monitoring, and log management, created by Doug Burks and maintained by Security Onion Solutions.


Security Onion is a free SOC platform built on Ubuntu and Elastic (with OpenSearch options) that integrates leading open-source security tools: Suricata or Zeek for network IDS, Wazuh for HIDS, Stenographer for full packet capture, Strelka and CyberChef for file inspection, Elastic Stack for storage and search, and a custom SOC web UI for case management and pivoting. Originally released by Doug Burks in 2008 and now developed by Security Onion Solutions LLC, the distribution is widely used for training (SANS SEC503), small and mid-sized SOCs, and incident response labs. Security Onion 2.x supports distributed deployments with manager, search, sensor, and storage nodes, and ships with thousands of pre-built detection rules.

Examples

  1. 01

    Investigating an alert from Suricata in Security Onion by pivoting to the Zeek connection log and PCAP for the same flow.

  2. 02

    Using the built-in Wazuh module to detect file-integrity changes on a Linux web server.

Frequently asked questions

What is Security Onion?

A free, open-source Linux distribution for threat hunting, network security monitoring, and log management, created by Doug Burks and maintained by Security Onion Solutions. It belongs to the Defense & Operations category of cybersecurity.

What does Security Onion mean?

A free, open-source Linux distribution for threat hunting, network security monitoring, and log management, created by Doug Burks and maintained by Security Onion Solutions.

How does Security Onion work?

Security Onion is a free SOC platform built on Ubuntu and Elastic (with OpenSearch options) that integrates leading open-source security tools: Suricata or Zeek for network IDS, Wazuh for HIDS, Stenographer for full packet capture, Strelka and CyberChef for file inspection, Elastic Stack for storage and search, and a custom SOC web UI for case management and pivoting. Originally released by Doug Burks in 2008 and now developed by Security Onion Solutions LLC, the distribution is widely used for training (SANS SEC503), small and mid-sized SOCs, and incident response labs. Security Onion 2.x supports distributed deployments with manager, search, sensor, and storage nodes, and ships with thousands of pre-built detection rules.

How do you defend against Security Onion?

Defences for Security Onion typically combine technical controls and operational practices, as detailed in the full definition above.

What are other names for Security Onion?

Common alternative names include: SO, Security Onion 2.

Related terms