2.1 Introduction

Team-Fly    

 
Malicious Mobile Code: Virus Protection for Windows
By Roger A. Grimes
Table of Contents
Chapter 2.  DOS Computer Viruses

2.1 Introduction

Ten years ago, many computer experts predicted the pubescent fad of writing computer viruses would fade away. Virus after virus was just redoing the same thing. What adrenaline rush could there be in creating something that a thousand others had already done? But like bell-bottom jeans and bad disco, malicious mobile code is growing ever popular.

There are a lot of other types of non-DOS, platform-specific viruses (Macintosh, Linux, OS/2, etc.) in the computer world, but it was the worldwide acceptance of IBM-compatible personal computers with Intel figs/u2122.gif microprocessors running DOS-based programs that provided the richest growth medium for malicious mobile code. There were already several other PC platforms in existence prior to the release of the IBM PC in October 1981, but none captured widespread public interest. As IBM-compatibles became ubiquitous, so did writing rogue programs.

The sheer number of DOS computer viruses easily account for a large portion of malicious programs in existence, in spite of the fact that some dominant form of the Windows operating system has been in use for the last ten years. DOS-based computer viruses are so plentiful that they are considered by many to be the default malicious code model. To really understand malicious mobile programs, you must understand DOS-based computer viruses.

Computer viruses are nothing more than software programs intentionally written to use other host files or boot areas to spread themselves around without the computer owner's permission. They travel around on infected disks or across networks waiting to infect new PCs. People rarely know their disks or programs are infected until the virus has been around awhile. The infection may or may not be outwardly visible, as the virus may not want to be found. The virus may or may not mean to cause intentional damage. In either case, viruses increase the risk of system or data corruption by modifying the host file or boot area. Computer programs aren't all that stable without unauthorized modifications being made. Depending on the type of virus, it may or may not increase the size of the host file. Viruses slow down the processing of your computer, and sometimes distinctively so.

Some viruses quickly infect hundreds of files in a matter of minutes. Others slowly and selectively infect their victim files to maximize the amount of time they can escape detection. The slower ones scare antivirus researchers more. Viruses that spread quickly are noticed and eradicated quickly, too. An antivirus researcher's nightmare is a virus that goes unnoticed for years with minimal detection, and by the time it is noticed, the damage is wide-spread and unstoppable. A PC provides lots of places malicious mobile code can hide.


Team-Fly    
Top


Malicious Mobile Code. Virus Protection for Windows
Malicious Mobile Code: Virus Protection for Windows (OReilly Computer Security)
ISBN: 156592682X
EAN: 2147483647
Year: 2001
Pages: 176

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net