This study aims to explore the social roles of the people who can influence young home computer users (HCUs) in Vietnam, as well as the interactions that make those people influential. Since HCUs are considered the weakest link in the security chain and cyber-threats can attack organisation’s information systems indirectly via these HCUs, it is therefore necessary to identify their sources of security influence for designing effective intervention. To this end, the ego-centric network analysis approach was employed to analyse the personal networks of security influence of 116 HCUs, comprising 548 influential sources in total. Close relationships such as family members, partners, friends, and colleagues were predominantly nominated as capable of influencing HCUs’ security behaviours. Furthermore, these sources influence the HCUs by possessing the power bases of expert, reward, and coercive, as well as holding legitimate positions that make them influential.