Analyzing security anomalies is the most effective way to detect security incidents, as it involves comparing the current state of the information system and network with the expected or normal state, and identifying any deviations or irregularities that may indicate a security breach or compromise. Security anomalies can be detected by using various tools and techniques, such as security information and event management (SIEM) systems, intrusion detection and prevention systems (IDS/IPS), log analysis, network traffic analysis, and behavioral analysis. (From CISM Review Manual 15th Edition)