Nowadays every organization is exposed to the intrinsic risks associated to the use of Information Technology. Cyber threats are more powerful and dangerous all the time. Data breaches cost organizations millions of euros every year. Therefore, they must prepare and protect infrastructures for such attacks even anticipating them if possible. A SIEM implements a set of technologies able to help detect, respond, and neutralize cyber threats. The main objective is to give an organization a global vision of IT security, allowing to have its complete control. By collecting and managing information about events that take place it is easier to detect trends and focus on anomalies. But the cost involved in purchasing, deploying, and customizing a commercial SIEM is high and beyond the budget of many organizations. This document is not intended to be an in-depth dissertation about the matter, rather it is a starting point that gives organizations with limited budgets ideas on how to use the Elastic Stack or the OpenSearch project, based on the experience of the ProTego.