Offloading decisions for computation-intensive applications in mobile cloud computing may involve many decision factors. Important decision factors such as offloading node reliability and privacy protection have not been well studied. Moreover, existing offloading models mainly focus on the one-to-one offloading relation. To address the multi-factor and multi-site offloading mobile cloud application scenarios, we present a multifactor multi-site risk-based offloading model that abstracts the offloading impact factors as for offloading benefit and offloading risk. The offloading decision is made based on a comprehensive offloading risk evaluation. This presented model is generic and extendible. Four offloading impact factors are presented to show the construction and operation of the presented offloading model, which can be easily extended to incorporate more factors to make offloading decision more comprehensive. The overall offloading benefits and risks are aggregated based on the mobile cloud users' preference. The performance evaluation presents the practicality of the presented solution.