In order to prevent attacks against smartphones and tablets, dedicated security applications are deployed on the mobile devices them-selves. However, these applications may have a significant impact on the device resources. Users may be tempted to uninstall or disable them with the objective of increasing battery lifetime and avoiding configuration operations and updates. In this paper, we propose a new approach for outsourcing mobile security functions as cloud-based services. The out-sourced functions are dynamically activated, configured and composed using software-defined networking and virtualization capabilities. We de-tail also preliminary results and point out future research efforts.