Wazuh is a free, open source and enterprise-ready security monitoring solution for threat detection, integrity monitoring, incident response and compliance.
Security Onion Usage¶
Security Onion uses Wazuh as a Host Intrusion Detection System (HIDS). Wazuh is monitoring and defending Security Onion itself and you can add Wazuh agents to monitor other hosts on your network as well.
The main configuration file for Wazuh is
If you want to send Wazuh logs to an external syslog collector, please see the syslog-output section.
Sometimes, Wazuh may recognize legitimate activity as potentially malicious, and engage in Active Response to block a connection. This may result in unintended consequences and/or blacklisting of trusted IPs. To prevent this from occurring, you can whitelist your IP address and change other settings in
<global> <white_list>desired_ip</white_list> </global>
You can add new rules and modify existing rules in
Wazuh alerts of a level of
5 or greater will be populated in the Sguil database, and viewable via Sguil and/or Squert. If you would like to change the level for which alerts are sent to sguild, you can modify the value for
/etc/nsm/securityonion.conf and restart NSM services.
Please note! It is important to ensure that you download the agent that matches the version of your Wazuh server. For example, if your Wazuh server is version 3.8.2, then you will want to deploy Wazuh agent version 3.8.2.
You may need to run so-allow to allow traffic from the IP address of your Wazuh agent(s).
Maximum Number of Agents¶
Security Onion is configured to support a maximum number of
14000 Wazuh agents reporting to a single Wazuh manager.
ossec-authd, be sure to add a firewall exception for agents to access port
1515/tcpon the Wazuh manager node:
sudo ufw allow proto tcp from agent_ip to any port 1515