Viruses and Other Software Threats › Spreading Contaminated Software › Infecting the Operating System

Infecting the Operating System

Although viruses are considerably more difficult to construct for the z/OS operating system than for WinTel PCs, viruses are possible from a technical point of view. The z/OS operating system was designed to support multiple users, so it has many of the internal controls that PCs lack. Internal control mechanisms, such as the Authorized Program Facility (APF), distinct problem (user) and supervisor (system) states, and storage protection keys, make it possible for z/OS to support and protect multiple users and itself. Different address spaces separate users from each other and the operating system. However, because users must share system programs (such as LPA, linklist, or application programs), insufficient security controls would make the z/OS operating system vulnerable to viral attack.