OSSEC vs OWASP Four Clover

OSSEC is an open-source host-based intrusion detection system for monitoring systems and network components. It analyzes logs, checks file integrity, monitors the Windows registry, detects rootkits, and can alert users in real time or take active response actions. Monitoring can be agent-based or agentless, and a centralized server applies policies across operating systems, with server-specific overrides. Alerts can use SMTP, SMS, and syslog; active response can block an attack immediately. The system runs on Linux, OpenBSD, FreeBSD, macOS, Solaris, and Windows, and supports self-hosted and cloud environments. OSSEC and OSSEC+ use command-line management; Atomic OSSEC editions add a management console and integrations with cloud services and other tools. OSSEC+ adds machine learning, ELK integration, threat sharing, and additional rules. Free OSSEC is listed at free; OSSEC+ is also free, with registration required. Atomic OSSEC is $5 a month per device. Atomic OSSEC SaaS offers a free 14-day trial for up to 10 endpoints.

OWASP Four Clover has no write-up on Specifiction yet; its figures are above.