A substantive body of research has emerged exploring the social dynamics and subculture of computer hacking. Few, however, have considered the structure of social networks in the hacker community due in part to the lack of visible information about active hackers or malware writers. Our research focuses on the rarely studied subject of underground networks of computer hackers. Thus, this study explores the social networks of a group of Russian hackers using publicly accessible data to understand the nature of social relationships and the ways that they affect information sharing and action. The findings demonstrate that there are a limited number of highly skilled hackers relative to those with some knowledge of computers. Additionally, those hackers with substantive technical skills are centrally located within friendship networks and are the focus of greater attention overall. The impact of these findings for our understanding of computer hacking, and peer networks generally are considered in detail.