OSSEC (Open Source Security) is an open source, host-based, intrusion detection system (IDS) which performs log analysis, file integrity checking, rootkit detection, and policy monitoring, and then provides real-time alerts. OSSEC also includes active response features for use after an alert through its Security Information and Event Management (SIE/SIM) components. Alerting is done through email and syslog. Logs can be exported to the Q-Log® or any other syslog or SIEM system. OSSEC provides intrusion detection for systems running Windows, Mac, Linux, Solaris, AIX, HP-UX, BSD, and VMware ESX.
OSSEC also allows network administrators to check for, and certify, PCI DSS 1.2/2.0 compliance, which is essential for securing Point-of-Sales (PoS) networks that accept credit cards.