Reviews Technology: Virus Definitions

1 - Definition

Viruses are small programs that hackers can destroy or disrupt some components of a computer (operating system, hard drive, files). This contamination was especially for source, the transfer of data from the Internet or floppy disk.

Some programs may not cause any damage and still be classified as viruses because they are undesirable. Indeed, viruses are generally characterized by the following two lines:

- An attempt to conceal their actions;

- The ability to spread as widely as possible all functions of the computer.

In short, a computer virus is a harmful program that waits for a predetermined condition (date, time, sequence, operation) to become active.

2 - Process of contamination

The virus introduced into a computer when it loads into its memory files infected. Files-programs are more likely to contain viruses (they usually have the extension EXE or COM). However, files from applications that can run macros, such as word processing, spreadsheets and software databases are also likely to be contaminated.

Image files, audio, video and e-mail messages are not dangerous. For cons, the files attached to an e-mail should be used with caution.

To "catch" a virus, the user must necessarily execute or open the infected file. Simply download a file without opening it does not contaminate your computer.

Executable files (EXE and COM extension) and files may contain macros could be systematically analyzed for viruses before opening.

3 - Mode of action of virus

The virus spreads in two ways:

- By adding data to a program where an increase in file size;

- By substituting their data with the program, thus changing the content without increasing the file size.

Viruses that do not increase the size of the programs are somewhat more difficult to detect. Indeed, checking the size of programs is a technique used to detect the presence of viruses.

Viruses Added inserted at the beginning of a program and increase the size. The virus, which is then launched before the program generally tries to infect other programs, leaving an imprint that will eventually recognize.

The virus contaminates first alternative software that does not contain his signature, and then verify the presence of a condition determined to decide whether or not they commit their crimes.

4 - Consequences of virus attacks

There is no universal convention for identifying viruses. However, they are generally classified into two types:

- Those that deal with applications.

- Those who attack the system.

There are now more than million viruses classified by major software companies. Note, for example, the virus and its variants INT_10 who move from one computer to change the size of the program operating system and disrupt the input/output. The virus PING and his variant PINGPONG, meanwhile, operate the screen erratically: the characters fall apart randomly and literally fall to dust down the screen.

Some viruses destroy hardware components of the computer. For example, they can force a hard drive to destroy itself by erasing the information essential to its existence, or by making repetitive and rapid movements that make use within hours.

Alterations are more subtle, less likely it is that the virus is detected.

Moreover, Computer viruses tend to grow faster than they managed to identify and limit the damage. Even the most harmless viruses can cause irreparable damage when modifying a file or paralyzing a computer in a crucial context.

5 - Rules Driving preventive

The best way to protect yourself from viruses is to purchase and install on all computers software detection virus and make regular update.

Other rules of conduct are:

- Always check with an anti-virus files attached to emails before opening them, especially if they come from an unknown source;

- Protect the floppy or Flash memory in writing, which prevents unwanted writing on the magnetic surface;

- Protect particularly original software by copying them before installing them;

- Make regular backup copies of most sensitive data;

- Test first on a standalone computer programs intended for use network;

- Establish a process to secure access to the LAN, and limited to only those authorized physical access to network servers.

- Never download software from unauthorized sites; (licensed sites are produced by software manufacturers, distributors or sites recognized in the Internet community in the case of freeware and shareware);

- Never open it without having previously verified files may contain macros (documents word processing, spreadsheets or databases, etc.).

- Never copy of pirated software;

- Never use floppies or Flash memory of unknown origin such as floppy disks or Flash memory

6 - Rules of Conduct vs viruses

In case of virus attack, the first instinct should be to stop the infected computer. It must then identify the disk (s) contaminated (s) so that all computers have used this source of contamination.

When using a network, it must also avoid restarting the computer infected by isolate failing to pass the "silly" to other computers.

The last step is to eliminate the virus With anti-virus and reinstall the programs that have been destroyed. containing games.

Overview of Anti-Virus

A virus is a computer program used to detect and eliminate known viruses. As new viruses appear constantly, anti-virus are frequently updated to be able to handle the latest "infections". We must always take care to get the latest version of antivirus software to be protected.

There are several anti-virus software offering types and various degrees of protection:

- some anti-virus check discs;

- Others may occur in the event of a launch executable (EXE or BAT);

- Others specialize in the verification of content arriving from the Internet.

The anti-virus go under the microscope all the bytes of a hard disk, a floppy disk or Flash memory or a file. Once they Celent the presence of a sequence suspicious, they inform the user and request authorization to destroy. According to the virus which anti-virus attacks, it is possible that the whole system again become clean once finished.