Part One
A. When the anti-virus program was downloaded, installed and a scan done on the whole computer system, no viruses were detected.
B. After a day, the antivirus program was updated and a scan done on all disks and mails. A virus contained in an email attachment in the form of an executable file was detected and deleted.
Part Two
Generally, a virus is an executable program that replicates itself without the user's knowledge, and can have varied effects on the computer system depending on the intention of the programmer. Below are some descriptions or viruses that exist in the current technology world (Stamp, 2011).
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The “Ogre” virus is one which resides in the hard disk and originates from the United States of America. It is a hugely destructive virus which gets active after detecting that the computer has been on for forty eight hours. It starts by warning the user not to switch off the power or even remove any external storage media connected to the computer. The virus encrypts all the data on the hard disk destroying all of it using the XOR method. After it is done, it displays a message informing the user that they can switch off the computer and wishes the luck. All the data is destroyed and can be recovered by decrypting (Disk Killer, n.d.).
The “crash” virus, which has its origin in Russia, is a non-resident one and affects COM files. It has no effect on the computer but sometimes displays garbage on the screen. It displays what appears to be an executing code (Virus and Threat, n.d.).
The “Swiss Army” virus is resident in the boot sectors of different drives and is three sectors long. It affects the DOS boot sectors of floppies and active partitions of the hard disk. When February seventh comes, it overwrites part of the hard disk (Swiss_Boot, n.d.).
References
Virus and Threat Descriptions.(n.d.). Retrieved December 29, 2012, from
Disk Killer.(n.d.). Retrieved December 29, 2012, from
Swiss_Boot. (n.d.). Retrieved December 29, 2012, from
Stamp, M. (2011). Information Security: Principles and Practice (ed. 2). New York: Wiley.