About computer virus
What is computer virus?
Computer virus is a special and altitude program that invade to other computers through some various mail browsers or circulating web browsers , etc in Internet society. This program has various functions, for example, deleting memory file on hard disk, indicating something that makes someone unpleasant, changing password automatically.
Also “The standard of computer virus measure” that the ministry or trade and industry enacted on April 10th in 1992 defines that computer virus is a program that gives injury to a third party’s program or database, and it has more than one function of next.
・The function of computer virus
Computer viruses have three functions. First function copy other files is system functions and infect them. This is said “oneself infection function”. Next function do nothing until computer fill a particular condition (a particular time, the number of handled times, etc …). And final function destroys sine programs, data, and files after becoming sick. This is said “becoming sick function” Then computer virus gives damage to our computers with these functions.
・The menace of computer virus
Computer viruses communicate to computers and propagate oneself. For example, first if a computer catch virus, the computer’s files gradually catch virus and virus program oneself. Then virus is getting activity and spread virus to a lot of computers with history of mail’s send and reception, etc. So computer viruses are around the world by such this route.
・The Trojan horse, back door, bot
These viruses that you probably know are worse in viruses. The Trojan’ horse is a machine of Greek myths and it means clever trap. This program go underground hide in computer and allows other computer to invade. On one hand, backdoor makes some back doors to invade and do remake control with other computers freely. This back doors is a virus, and do remake control. But it is likely that it infect with other virus. So the amount of damages is bigger. Bot is worst among three. This virus do remote control as backdoor, but it hot only leak information but also make computers unusual though sending bother mails with virus, attacking to server, making routers to infect to server by a main computer. The terrible thing in this situation is that controlled computer’s owner become a assailant. The measure to bots is very important not to be assailant.
Bibliography
そうだったのか！セキュリティ対策ソフトのしくみと基礎用語
http://azby.fmworld.net/usage/closeup/20120725/page2.html
総務省 国民のための情報セキュリティサイト
http://www.soumu.go.jp/main_sosiki/joho_tsusin/security/index.htm