Biological viruses: Viruses are composed of a nucleic acid molecule (DNA or RNA) and a protein (Protein) or only a protein (such as a prion). The virus is tiny and has a simple structure. Viruses have no cellular structure and cannot replicate themselves because they do not have the basic systems necessary to achieve metabolism. But when it comes into contact with a host cell, it takes off its protein coat, and its nucleic acid (gene) invades the host cell, using the latter's replication system to replicate new viruses according to the instructions of the viral gene.
Computer virus: Computer virus (Computer Virus) is a set of computer instructions or program codes that the programmer inserts into a computer program to destroy computer functions or data. It can affect the use of the computer and can replicate itself.
Computer viruses are communicable, covert, infectious, latent, excitable, expressive or destructive. The life cycle of a computer virus: development period → infection period → incubation period → attack period → discovery period → digestion period → extinction period.
A computer virus is a program, a piece of executable code. Just like biological viruses, they have the characteristics of self-reproduction, mutual infection, and activation of regeneration. Computer viruses have unique replication capabilities. They can spread quickly and are often difficult to eradicate. They can attach themselves to various types of files and spread with them when they are copied or transferred from one user to another.
Viruses rely on storage media such as floppy disks and hard disks to form a source of infection. The vector of virus transmission depends on the work environment. Virus activation is to store the virus in the memory and set trigger conditions. The trigger conditions are diverse and can be the clock, the system date, the user identifier, or a system communication, etc. When conditions are ripe, the virus begins to replicate itself into the infected object and carry out various destructive activities.
Virus infection is an important indicator of virus performance. During the infection process, the virus copies a copy of itself to the infected object.