This paper presents a new monitoring tool called SYNEMA that helps to visualize different types of alerts from well-known security sensors. The architecture of the proposed tool is distributed and enables centralizing the collected information into a lightweight visualizer. The front-end proposes many display modes in order to give the ability to clearly see malicious activities and to be able to visually monitor information collected at system, network and user level in the hosts. The paper concludes with development perspectives about an auto-configurable plugin for visual correlation of attacks.