In this article, we present a model of cyber attacks which can be used to represent a cyber attack in an intuitive and concise way. With ever-increasing popularities of online services, we have seen a growing number of cyber attacks targeted towards large online service providers as well as individuals and the IoT devices. To mitigate these attacks, there is a strong urge to understand their different aspects. Creating a model is a widely used method towards this goal. Unfortunately, the number of models for cyber attacks is pretty low and even the existing models are not comprehensive. In this paper, we aim to fill this gap by presenting a comprehensive cyber attacks model. We have used this model to represent a wide range of cyber attacks and shown its applicability and usefulness. We believe that our model will be a useful tool for the formal analysis of cyber attacks.