A computer virus can be defined as a program that hurts and alters the normal functioning of a computer. Its purpose is to spread and cause harm to the greatest number of users, infecting files and the operating system on your hard drive.

These are programs that run, replicate and propagate themselves. That is why his name is similar to biological viruses that affect humans.

Spain receives a large number of computer virus infections. He currently occupies one of the first places in the ranking European infections.

Methods of propagation

The main way they have the virus is spread through the exchange or download files. The contagion can be done through two means:

·  Internet: it is now the most widely used method for the spread of viruses. They usually come via e-mail or downloading files from web pages.

·  The disk drives: are another way for a virus to spread because they are stored files (attachments, or downloaded tablets), programs, etc. Among the units are most often used CDs, DVDs, floppy disks or removable.

The spread of a virus is carried out by order of action. This can be given by the creator of the virus or inadvertently caused by the user.

Techniques to detect a virus

There are several ways to tell if a computer is infected with a computer virus:

·  The scanner or tracing involves malicious codes look at the files or existing files in a storage unit, such as CDs or DVDs, to isolate them later.

·  Monitoring programs: their role is to detect the harmful activity that performs a virus and act accordingly.

·  The heuristic scanner: is the search for virus through artificial intelligence techniques. It complements the scanner.

Disposal Methods

The virus is a computer program through which prevents potential virus infection, in addition to clean existing ones. These programs should be updated periodically in order to eliminate the virus-ups.

In seeking these virus programs analyze your computer's memory, then the boot sector, and finally each of the executable files.

Some antivirus deletes the file or file directly infected, but there are others who need a special program to eliminate them. Therefore, the virus must be regularly updated.

Firewall

The firewall is the means (computer, router, the program), which prevents access stranger to a computer connected to a network.

To avoid such access needs to be configured by the user. This is a simple foresight, has no program to eliminate threats such as antivirus.