Answer:
c) Trojan horse
Explanation:
A Trojan horse is designed to damage, disrupt, steal, or in general inflict some other harmful action on your data or network. A Trojan acts like a bona fide application or file to trick you. Once installed, a Trojan can perform the action it was designed for.
If a set of instructions to increase a programmer’s pay rate by 10 percent is hidden inside an authorized program and it changes and updates the payroll file, then this instructions called a Trojan horse.
A trap door, also known as a back door, provides a secret or undocumented method of gaining access to an application, operating system or online service.
A virus worm is a malicious, self-replicating program that can spread throughout a network without human assistance
