SIEM: Centralized Security Intelligence
Systems, networks, firewalls, and applications all generate thousands of log entries every second. A human cannot monitor this volume of data.
A SIEM (Security Information and Event Management) system centralizes, correlates, and analyzes security data from multiple sources to provide a unified view of the security posture.
SIEM Functions
- Aggregation: Gathers logs from everything (servers, network devices, applications) into one place.
- Normalization: Translates diverse log formats into a common format.
- Correlation: Uses rules to link seemingly unrelated events to identify a security incident (e.g., 'Failed login on server A followed by successful login on server B using the same username').
- Alerting: Generates high-priority alerts for security analysts.
Example Tools: Splunk, ELK Stack (Elasticsearch, Logstash, Kibana), Microsoft Sentinel.