Cloud infrastructure becomes the primary business environment for all types of enterprises during recent years. In cloud computing security is a fundamental concern, loss of control and potential lack of trust prevent large set of potential customers to immerse in the cloud world. One of the major key problem is how one can test, monitor or measure the underlying Cloud infrastructure from user/customer space. We have developed a solution which is able to examine the infrastructure, from security point-of-views. We offer a clear, adaptable, concise and easy-to-extend framework to assess the underlying cloud infrastructure. Our developed solution is generic and multipurpose it can act as a vulnerability scanner, and performance benchmarking tool at the same time. It is virtualized, it is agent based and collects assessment information by the decentralized Security Monitor and it archives the results received from the components and visualize them via a web interface for the tester/administrators. In this paper we present our virtualized cloud security monitor and assessment solution, we describe its functionalities and provide some examples of its results captured in real systems.