Chapter 1. Introduction; Computer Viruses And Malware - KAPERSKY ANTI-VIRUS 5.7 - FOR LINUX FILE SERVER Administrator's Manual

CHAPTER 1. INTRODUCTION

The constant growth in both the number of computer users, and the volume of e-
mail and internet traffic, increases the threat of virus infections and data
corruption or theft by malicious computer programs (malware).
The most dangerous sources of malware are:
Internet
The global information network is the main conduit for all types of mal-
ware. As a rule, viruses and other malicious programs are located on
popular internet websites, disguised as useful software or freeware.
Malware can also be located within scripts that automatically run when a
website is loaded in the user‟s browser.
E-mail messages
E-mail messages delivered to the user‟s mailbox and stored in e-mail
databases may contain viruses. Malware can be located either in the
message body, or as a message attachment. Commonly, infected e-mail
messages contain viruses or mail worms. When you open an e-mail
message or save an attached file to your hard drive, you may infect data
stored in your computer.
Software vulnerabilities
In most cases hackers‟ attacks are attempted using "software holes".
Such vulnerabilities allow hackers to obtain remote access to your com-
puter and, therefore, to your data, your LAN resources and other
sources of information.
Viruses targeting Unix-based systems are far less common than those aimed at
the Windows Operating System, due to the peculiarities of the two platforms.
However, the threat to Unix users is not negligible. Provided below is a detailed
description of malware types.

1.1. Computer viruses and malware

In order to be aware of potential threats to your computer, it is helpful to know
about the types of malicious software ("malware") and how they work. In general,
malicious programs fall into one of three categories:

Worms – malicious programs which spread themselves using network
resources. These programs are called "worms" due to their ability to tun-