The document examines security threats in virtualized cloud computing infrastructures, focusing on vulnerabilities of virtual machine monitors (VMMs) and potential attacks such as VM hopping, VM escape, and VM mobility. It emphasizes the need for robust security tools and techniques, including encryption, access control, intrusion detection tools, and virtual firewalls, to protect VMMs and ensure the integrity of the cloud infrastructure. The paper outlines both the inherent risks of virtualization and the essential strategies for mitigative security measures within a multi-tenant cloud environment.