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networking curriculum
support CD for senior
secondary studies

Topics
. Home
. Networking History
. Why network?
. OSI model
. Connecting up
. Protocols
. Technology
. Network types
. Topologies
. Issues
. Design factors
. Economic effects
. www links
. Site map
Print Formattednetworking > issues > Viruses

Viruses

A computer virus is a specially written program that is designed to create havoc on a computer. Viruses can do this in a variety of ways; some are simply annoying, like the Ping Pong virus that was a small dot that bounces around the screen; others can crash the computer and make it unusable, like the Michelangelo virus.

Virus programs are usually disguised as another type of file or attach themselves to a legitimate file. For example, there have been many e-mail viruses lately that appear as attachments that look like picture files but when the unsuspecting recipient tries to open the file, the virus activates itself. This may be a process of simply sending itself automatically to e-mail addresses in a user's address book or possibly completely crashing the computer. There are also a huge range of macro viruses that attach themselves to Microsoft Office files so that when an Office document is transferred from one computer to another, the virus file goes along too.

Many virus files that are attached to e-mails can be detected by their file extension. Files that end in EXE, BAT, PIF, COM and VBS are all file types that when activated will run a program. If you ever receive an e-mail with an attachment, do not open the file but delete the e-mail immediately.

Worms, such as the Blaster Worm, behave like viruses but do not rely on infected programs to spread. Many of the most recent debilitating attacks on computer networks have been worms rather than viruses.

worksheets
. history
. why network
. osi model
. connecting
. protocols
. technology
. topologies (tla)
. issues
. network types
. design
. economics
. economics (cs)
   - solutions -

quizzes
. why network
. osi model
. connecting
. protocols
. technology
. topology
. issues
. network types
. design
. economics

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