In the past few years, software engineering researchers have adopted social network analysis techniques to understand collaboration patterns in global software teams. In this paper, we investigate current research in global software development where social network theory is used as an analysis technique. We do so through a systematic literature review where we collect and analyze previous work that adopt a social network perspective in distributed software development. We use the 3C collaboration model to classify our results based on the communication, coordination and cooperation aspects of global networks. Our results reveal two main coordination structures used in distributed teams, namely the clustering and the core-periphery structure. The analysis of the cooperation activities of the global networks reveal differences between planning and practice. Finally, several tools have been identified that aim to improve communication patterns among distributed team members.