Security Information and Event Management (SIEM) refers to technology that provides real-time analysis of security alerts generated by network hardware and applications. SIEM works by gathering, analyzing and presenting information from a variety of sources of such information across the enterprise network including network and security devices; identity and access management applications; vulnerability management and policy compliance tools; operating system, database and application logs; and external threat data.
All compliance frameworks including PCI-DSS, HIPAA, FISMA, NERC etc call for the implementation and regular usage of SIEM technology. The absence of regular usage is noted as a major factor in post-mortem analysis of IT security related incidents.
Why is this the case? It’s because SIEM, when implemented properly gathers security data from all the nooks and crannies of the enterprise network. When this information is collated and presented well, an analyst is able to see what is happening, what happened and what is different.
It’s akin to letting in the sunlight to all corners and hidden places. You can see better, much better.
You can’t fix what you can’t see and don’t know. Knowledge of the goings-on in the various parts of the network, in real-time when possible, is the first step towards building a meaningful security defense.