CSC100-2 Kouhei Iwabuchi, Ann Brox, Tomomi Tsuchiya
Computer Viruses are very serious problem in these days. In AIU, almost all people use the Internet everyday not only in school but also in their own rooms. It is very important to know how to protect computers from computer viruses.
First, Trojan horse(1) is one of the examples of computer viruses. In the context of computing and software, a Trojan horse or simply trojan, is a piece of software which appears to perform a certain action, but in fact, performs another. Contrary to popular belief, this action, usually encoded in a hidden payload, may or may not be acutely malicious, but Trojan horses are notorious today for their use in the installation of backdoor programs. Simply put, a Trojan horse is not a computer virus. Unlike such badware, it does not propagate by self-replication but relies heavily on the exploitation of an end-user. It is instead a categorical attribute which can encompass many different forms of codes. Therefore, a computer worm or virus may be a Trojan horse. The term is derived from the classical myth of the Trojan Horse because it pretend to be a normal file like the Trojan Horse of class.
In the field of computer architecture, 'Trojan Horse' can also refer to security loopholes that allow kernel code to access anything for which it is not authorized. A simple example of a Trojan horse would be a program named "waterfalls.scr" where it's author claims it is a free waterfall screensaver. When run, it instead unloads hidden programs, commands, scripts, or any number of commands with or without the user's knowledge or consent. Malicious Trojan Horse programs are often used to circumvent protection systems in effect creating a vulnerable system to allow unauthorized access to the user's computer. Non-malicious Trojan Horse programs are used for managing systems, deploying software, surveillance, and forensics.
When I download music files from the Free MP3 websites, I sometimes get affected by these kind of Trojan, but my anti-virus software always protect me. One of my friend got seriosly affected by the Trojan and his PC became impotent to start up.
Second, “Logic bomb” is a type of computer virus made by crackers. “Logic Bomb” has a very big power to destroy large area. The amount of damage would be very big. “Logic Bomb” is booted by very small event, and destroys not only computer systems but also networks. If it infected a company computer, would give very serious damage on economy. The trigger of its boot is such as a coming of certain time, or a login of a certain user.
The most famous example of “Logic Bomb” is “Chernobyl (2)", This was found in Taiwan in June 1998. This was programmed to boot on April 26, which is the day that Chernobyl nuclear power plant exploded. This was very strong virus. Chernobyl infected the files of PE (Portable Executable) in the Microsoft Windows first. Then, by using the file, it infected memory and destroyed the information in the hard disc and Bios (Basic Input/ Output System) Rom. It was hard to find this virus because it did not leave its trace. Chernobyl virus brought chaos and infinite damage in Turkey and Korea and so on. Especially in Korea, it is said that about 1,000,000 computers got this virus and the amount of damage was 250,000,000 dollars.
As another example, one of my friends got a type of logic bomb, which restarts her computer at 11:53 every night. It is not such a serious one as Chernobyl but it makes people irritated.
Third, a computer worm resembles the computer virus, but has a few more abilities. It can spread on its own and unlike the computer virus; it does not need to be manually started by a person. If a computer program, like an e-mail program or an operating system, has a weakness, the computer worm can in some cases exploit the weakness.
The computer worm infects a computer with weak or no protection, starts its self and then look for other computers it can infect. It can find new computers to infect by directly searching the internet, or it can send a copy of it self to everyone in the address book on the infected computer or to every one on the friends list of an instant messaging program.
Consequences: In the past computer viruses, computer worms and Trojan horses often did not have any other purpose than showing of the programmers skills. Nevertheless, some of them could also destroy the computer and delete information.
After the use of the internet spread, the possibility to make easy money of non-suspecting users has become greater and greater. Most malicious programs have been equipped with the possibility to make money for the creator of the program, in one way or another.
Here is a few ways an infected computer can make someone money:
Ÿ By being a mail provider for people sending spam. Your computer receives a spam-mail and then sends it to millions of recipient without you even realizing it.
Ÿ By being part of a DDoS-attack (distributed denial of service attack). A person can extort money from high profile web sites by threatening to do a DDoS-attack. A DDoS-attack is basically done by bombarding the web site with requests until the site cannot handle all the requests and shuts down.
Ÿ By spying on the owner of the computer and give information to an analyzing agency, witch in return delivers commercial.
Ÿ But worst of all: by lurking on your computer to collect secret information, like passwords, account numbers and much more, and either sell it to someone who can miss use it or they can miss use it them selves.
To avoid the damage from these kinds of computer viruses, it is very important to do some precautions. First, take backup data regularly. Second, install the programs, which protect computer system from viruses or use The Mozilla Firefox (Picture 1) instead of Internet Explorer(Picture2) because it is safer. But many people are still using IE rather than Firefox. This is shown in Chart 1. Third, there are some free computer anti-virus soft wares on the internet. So, Download it and use it. It is important to be updated. Fourth, Use Microsoft outlook function to not send emails automatically so you won’t send an email which contains viruses to many people. And also, windows has firewall function which block viruses such as Trojan hourse or worm from the Internet. Therefore it is essential to make sure the function is working. The easiest way to peotect computers is not to open the attached file that you don’t know. Computer viruses are not special thing. So, having knowledge of them and be cautious with them are necessary.
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