What type of assets must be protected in operating systems?

Protecting main memory and programs within an operating system is crucial because they are fundamental to the system's operation and security. Main memory, or RAM, holds the data and instructions that the CPU needs to perform tasks. If this memory is compromised, malicious actors can manipulate processes, leading to unauthorized access or data loss.

Programs also need protection since they can contain sensitive information and perform critical functions. Compromised programs can lead to vulnerabilities being exploited, allowing attackers to gain control over the system or access confidential data. Therefore, both main memory and programs are essential components that must be safeguarded to ensure the overall security of the operating system.

While application variables, hardware devices, and user credentials also require protection, the focus on main memory and programs highlights the core components of the operating system that directly impact its functioning and security.