The adoption and integration of a multi-cloud computing environment for data transmission and storage is a crucial step for organizations, offering optimization, redundancy, and increased accessibility. However, this transition has also brought about significant security challenges, vulnerabilities, and attack vectors. These include inefficient resource management across diverse cloud providers, interoperability issues, identity and access management concerns, unauthorized access, data governance, and operational optimization. These challenges have led to various types of attacks, such as supply chain attacks, data breaches, DoS, APTs, and cross-cloud attacks. This paper delves into the growing complexities of securing multi-cloud environments, specifically focusing on governance and security implications. It also evaluates the effectiveness of multi-cloud management tools, such as Azure Arc and Google Anthos, in addressing these challenges. The contribution of this paper is threefold. First, we thoroughly investigate the various multicloud data storage mechanisms, vulnerabilities, and attacks. Secondly, we compare three prominent multi-cloud management tools, Azure Arc, Google Anthos, and AWS Elastic Kubernetes Service (EKS), regarding their ability to secure resources across diverse cloud providers. Finally, we conduct an attack on the multi-cloud platform to detect vulnerabilities and operational inefficiencies and propose security mechanisms to enhance security. Our results demonstrate how data security and governance can be effectively implemented to secure multi-cloud operation environments and how inefficiencies can be detected and addressed to ensure data security.