How do technologies matter for security politics? This article introduces the kind of arguments an 'infrastructural approach' would focus its answer on. It illustrates how the approach would work by focussing on how the spyware Pegasus developed by the Israeli company NSO matters for Swiss security politics. It follows the infrastructural approach showing how and why it would tend to three things primarily: the politics of the 'infrastructures' Pegasus is inscribed in, the politics of the processes of 'infrastructuring' the software generates and the 'infrapolitics' that sustain and transform these processes and infrastructures. The article also discusses the strengths and weaknesses of infrastructural approaches, underlining that since they are relational, processual and radically open epistemologically and ontologically, infrastructural approaches are suitable for opening new agendas, re-problematising and re-imagining the politics of security technologies. They are less suited for studies premised on a fixed understanding of the politics of security technology.