Understanding Computer Security: Principles and Virus Protection

The Concept of Invulnerability

The ability to avoid being harmed by external attacks is called invulnerability. While there are many myths, legends, and historical accounts regarding the search for such invulnerability, all these strategies have historically proven to have weaknesses.

Requirements for a Secure Computer System

Specific computer-level characteristics have been established that a truly invulnerable computer should fulfill:

• Be installed more than 20 feet underground.
• Remain disconnected from any other computer.
• Be isolated from the outside in a concrete structure.
• Possess an independent electrical system.

The Paradox of 100% Security

A 100% secure system is effectively 0% operational. Although it might be invulnerable to climatic disasters, prevent the entry of intruders, and resist virus attacks, it would serve no purpose because no one could use it; it would not be functional.

Core Pillars of Computer Security

Computer security includes the set of analysis tools and methodologies used to maintain:

• Privacy: Information is not accessible to unauthorized persons.
• Integrity: Information is only modified by authorized personnel.
• Operability: Information is available when needed.

Essential Security Tools

The three basic tools used in computer security are:

• Antivirus: A program designed to detect, identify, and eliminate known viruses.
• Backup: A program that allows you to make regular copies of the information produced by the system.
• Access Control: A program that allows you to set priorities and define users authorized to work in the system.

Understanding Computer Viruses

Computer viruses are small, malicious programs that have the property of hiding and replicating themselves. They often include sophisticated techniques of concealment and defense, known as stealth techniques.

Virus Infection vs. Damage

The fact that a system is infected with a virus does not necessarily mean it has been damaged. Before producing significant damage, the virus typically attempts to replicate and generate copies of itself.

Classification of Viruses

Based on their mode of transmission, viruses can be classified into:

• Executable file virus: These are located at the beginning of a file, so that every time the file is opened, the virus runs first.
• Boot viruses: Every time you turn on a computer using an infected disk, the virus runs first and infects the boot sector of your hard disk.
• Macro virus: These have achieved widespread distribution and infect files containing macros, such as programs in Word, Excel, or Access.