Viruses and malware infect millions of computers that some of you may see breaking news daily. In general, attackers often use these malicious programs to steal user data, blackmail businesses, and even bring down national networks, causing billions of dollars in damage per year. This course provides the basics of various security attacks and vulnerabilities (e.g., Buffer Overflow) in Windows and Linux systems and effective prevention methods. From understanding the basics of malicious programs and software security analysis such as assembly programming and reverse engineering, you can know how attackers build malware/viruses and propose a proper defense approach. You will also learn about system forensics through Kali Linux and advanced tools (e.g., Metasploit) to trace security vulnerabilities and corresponding attacks. Finally, DevSecOps and building security APIs, a critical software security development skill for network administrators and secure software developers, are introduced.