This document proposes a security management framework to protect cloud storage systems from complex attacks. It introduces a model that enforces security policies defined by cloud providers. The framework can interface with different cloud data management systems and detect both predefined and customized attacks. It evaluates user behavior and identifies malicious activity patterns based on thresholds defined in security policies. The framework was implemented on a testbed and experiments showed it can efficiently defend storage systems by evaluating policies. This generic approach provides flexible security while maintaining high performance for cloud services.