Cloud computing is one of the most smart technology in the era of computing as its capability to decrease the cost of data processing while increasing flexibility and scalability for computer processes. Security is one of the core concerns related to the cloud computing as it hinders the organizations to adopt this technology. Infrastructure as a service (IaaS) is one of the main services of cloud computing which uses virtualization to supply virtualized computing resources to its users through the internet. Virtual Machine Image is the key component in the cloud as it is used to run an instance. There are security issues related to the virtual machine image that need to be analysed as being an essential component related to the cloud computing. Some studies were conducted to provide countermeasure for the identify security threats. However, there is no study has attempted to synthesize security threats and corresponding vulnerabilities. In addition, these studies did not model and classified security threats to find their effect on the Virtual Machine Image. Therefore, this paper provides a threat modelling approach to identify threats that affect the virtual machine image. Furthermore, threat classification is carried out to each individual threat to find out their effects on the cloud computing. Potential attack was drawn to show how an adversary might exploit the weakness in the system to attack the Virtual Machine Image.