In this paper, we review the state of Internet of Things (IoT) security research, with a focus on recent countermeasures that attempt to address vulnerabilities and attacks in IoT networks. Due to the fact that IoT encompasses a large range of significantly distinct environments, each of which merits their own survey, our survey focuses mainly on the smart home environment. Based on the papers surveyed, we pinpoint several challenges and open issues that have yet to be adequately addressed in the realm of IoT security research. Lastly, in order to address these open issues, we provide a list of future research directions on which we believe researchers should focus.