Malicious software and antivirus
Virus lifecycle

Virus lifecycle consists of four phases:

In the dormant phase, the virus remains inactive, so it does not perform any activity at all. It is necessary to note though that not all viruses have this phase in their lifecycle.

In the propagation phase, the virus places an identical copy of itself into another program or into certain areas on the disk. Each infected program contains now a clone of the virus, which is able to propagate itself.

In the triggering phase, the virus is activated. This phase can be initialized by different conditions or states of the infected program.

In the execution phase, the virus performs the activity that was programmed during the virus creation. These are usually destructive activities which can cause the loss and damage of the information contained in the infected computer system.