Almost all software systems today face a variety of threats, and the number of threats grows as technology changes. Malware that exploits software vulnerabilities grew 151 percent in the second quarter of 2018, and cyber-crime damage costs are estimated to reach $6 trillion annually by 2021. Threats can come from outside or within organizations, and they can have devastating consequences. Attacks can disable systems entirely or lead to the leaking of sensitive information, which would diminish consumer trust in the system provider. To prevent threats from taking advantage of system flaws, administrators can use threat-modeling methods to inform defensive measures. In this blog post, I summarize 12 available threat-modeling methods.