平成 20 年度 大学院博士(前期)課程入学者選抜学力試験

英語[90 分]注 意 事 項1. 試験開始の合図があるまで, この問題冊子を開かないでください.
2. 問題は 1 ページから 5 ページにあります. ページ番号のついていない紙は下書き用紙です.
3. 解答用紙は 2 枚に分かれているので, すべての解答用紙の所定欄に受験番号と氏名をはっきりと記入してください.
4. 下書き用紙 2 枚が解答用紙と一緒にあります.
5. 試験中に問題冊子の印刷不明瞭, ページの落丁・乱丁および解答用紙の汚れ等に気がついた場合は,静かに手を上げて監督員に知らせてください
6. 試験終了後, 問題冊子および下書き用紙は持ち帰ってください.
7. .設問ごとに配点が記されていますPART 1: Reading comprehension
Read the article below and answer the following questions.

Google searches web's dark side
One in 10 web pages scrutinised by search giant Google contained malicious
code that could infect a user's PC.
Researchers from ①the firm surveyed billions of sites, subjecting 4.5 million pages to "in-depthanalysis". About 450,000 were capable of launching so-called "drive-by downloads", sites that
install malicious code, such as spyware, without a user's knowledge. A further 700,000 pages
were thought to contain code that could ②compromise a user's computer, the team report. To
address the problem, the researchers say the company has "started an effort to identify allweb pages on the internet that could be malicious".
Phantom sites
Drive-by downloads are an increasingly common way to infect a computer or steal sensitive
information. They usually consist of malicious programs that automatically install when apotential victim visits a booby-trapped website.
"To ③entice users to install malware, adversaries employ social engineering," wrote Google
researcher Niels Provos and his colleagues in a paper titled The Ghost In The Browser. "Theuser is presented with links that promise access to 'interesting' pages with explicit
pornographic content, copyrighted software or media. A common example are sites that
display thumbnails to adult videos."
The vast majority exploit vulnerabilities in Microsoft's Internet Explorer browser to install④

themselves. Some downloads, such as those that alter bookmarks, install unwanted toolbars
or change the start page of a browser, are an annoyance. But increasingly, criminals are using
drive-bys to install keyloggers that steal login and password information. Other pieces ofmalicious code hijack a computer turning it into a "bot", a remotely controlled PC.

1Drive-by downloads represent a shift away from traditional methods of infecting a computer,such as spam and email attachments.
Attack plan
As well as characterising the scale of the problem on the net, the Google study analysed themain methods by which criminals inject malicious code on to innocent web pages. ⑤It foundthat the code was often contained in those parts of the website not designed or controlled by
the website owner, such as banner adverts and widgets. Widgets are small programs that
may, for example, display a calendar on a webpage or a web traffic counter. These are oftendownloaded form third party sites.
The rise of web 2.0 and user-generated content gave criminals other channels, or vectors, of⑥attack, it found. For example, postings in blogs and forums that contain links to images orother content could unwittingly infect a user.
The study also found that gangs were able to hijack web servers, effectively taking over andinfecting all of the web pages hosted on the computer. In a test, the researchers' computer
was infected with 50 different pieces of malware by visiting a web page hosted on a hijackedserver.
The firm is now in the process of mapping the malware threat. Google, part of theStopBadware coalition, already warns users if they are about to visit a potentially harmful
website, displaying a message that reads "this site may harm your computer" next to thesearch results. "Marking pages with a label allows users to avoid exposure to such sites andresults in fewer users being infected," the researchers wrote.
However, the task will not be easy, they say. "Finding all the web-based infection vectors is asignificant challenge and requires almost complete knowledge of the web as a whole," theywrote.
(from http://news.bbc.co.uk/2/hi/technology/6645895.stm , words intact, but discrete sentences edited
into paragraphs.)

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Questions: Reading Comprehension

1. What does ①the firm indicate? Choose the best one from the following.
a. malicious code b. Google

c. web pages scrutinisedd. user’s PC

2. What does ②compromise mean? Choose the best one from the following.
a. be in between b. secure c. give and take(4 points)

d. endanger

3. What does ③entice mean? Choose the best one from the following.
a. attract b. prevent(4 points)(4 points)

c. enforce d. explore

4. What does ④The vast majority indicate? Choose the best one from the following.
(4 points)
a. most of the PC users

b. most of the drive-by downloads

c. most of the operating systems d. most of the “interesting” websites

5. What does ⑤it indicate? Choose the best one from the following.
a. the scale of the problem(4 points)b. the methods to inject malicious codec. the Google study d. the characteristics of the criminals

6. Judge true or false each statement below, according to the text.
(5 points each = total 30 points)
1) The research team, headed by Niels Provos, found that about 10% of thewebsites possibly contained malicious code.
2) Ways to spread malicious code have shifted from spam to exploiting e-mailattachments.

33) Web criminals have developed various ways to inject malicious code into
innocent websites.
4) The most serious types of damage caused by drive-by downloads are altering
bookmarks, installing unwanted toolbars or changing the start page of a browser.
5) Some of the criminal techniques for hijacking web servers are so sophisticatedthat even the researcher’s computer was once infected by malware.
6) Google will sell downloadable anti-virus software.

7. Translate the underlined part ⑥ into Japanese. (20 points)

4PART 2: Academic Skills
Answer the following questions about the research described in the article.

1. What was the goal of the study mentioned in the text? Answer in English within 20-40
words. (12 points)
2. What are the results of the survey and the conclusion of the researchers? Write asummary in English within 40-80 words. (18 points)

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