What type of virus infects executable files or applications?

A program virus is specifically designed to infect executable files or applications by attaching itself to programs that run on a computer. When the infected program is executed, the virus can activate, potentially leading to malicious actions such as data corruption, system slowdown, or further spreading to other executables on the system.

This type of virus operates by typically modifying the code of the host executable or by inserting its own code, which runs alongside the legitimate functions of the application. The nature of executable files, being the first step in any application’s execution process, makes them a prime target for this type of malicious software.

Other types of viruses, such as metamorphic viruses, have the ability to rewrite their own code to avoid detection but still can infect executables. Stealth viruses focus on hiding their presence from antivirus software but do not characterize the infection method as specifically as a program virus does. A general term like "virus" encompasses all forms of viruses but does not detail the specific behavior regarding executable files. Hence, the identification of the program virus is essential for understanding how such threats specifically impact applications.