A computer is a piece of programming code that is inserted into other programming to cause an unexpected and often-undesirable event for the victim.

A computer virus

Explanation:

A computer virus is categorized as malicious software that is built just like any other program out there to cause damage, steal, or disrupt a victim’s computer system. They infect systems and networks in various ways. Most are designed to move in stealth and attach themselves to other programs. Others, however, exploit an unpatched vulnerability and propagate themselves into harmful programs. Depending on how they are designed, most viruses insert a copy of themselves, spread rapidly from within files of a computer, and even extend to other computers in a network.