输入/输出系统主要用三种方式与主机交换数据，对于这三种方式的描述正确的是(1)。

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Pharming is a scamming practice in which malicious code is installed on a personal computer or server, misdirecting users to(71)fraudulent Web sites without their knowledge or consent. Pharming has been called "phishing without a lure".

 In phishing, the perpetrator sends out legitimate-(72)looking e-malls, appearing to come from some of the Web's most popular sites, in an effort to obtain personal and financial information from individual recipients. But in pharming, larger numbers of computer users can be(73)victimized because it is not necessary to target individuals one by one and no conscious action is required on the part of the victim. In one form. of pharming attack, code sent in an e-mail modifies local host files on a personal computer. The host files convert URLs into the number strings that the computer uses to access Web sites. A computer with a compromised host file will go to the fake Web site even if a user types in the correct Internet address or clicks on an affected(74)bookmark entry. Some spyware removal programs can correct the corruption, but it frequently recurs unless the user changes browsing.(75)habits.

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