threat-modeling

Works out what could go wrong in a system's design before it is built — who would attack it, how, and which defences are worth having. Use this whenever the user is designing a system that handles sensitive data, money, or authentication, asks what the security risks are, mentions threat modeling or STRIDE, or is starting a feature with a meaningful attack surface. This is design-time and systematic; for finding vulnerabilities in code that exists, use security-analysis.