問82
頻出度★★★
情報セキュリティに関する対策 a～d のうち, ウイルスに感染することを防止するための対策として, 適切なものだけを全て挙げたものはどれか。 a ウイルス対策ソフトの導入 b セキュリティパッチ (修正モジュール) の適用 c ハードディスクのパスワード設定 d ファイルの暗号化
平成26年度 春期 ITパスポート試験 問82
This question's explanation and your answers so far.
解説
問 82
- ア
正解 The correct answer is “ア (a, b)”. Two kinds of measures actually work to prevent virus infection: those that detect and block the virus itself, and those that close the holes a virus gets in through. The anti-virus software in a checks files against pattern files (virus definition files) to detect and remove known viruses, stopping mail attachments and downloaded files at the door before they run. Applying the security patches (fix modules) in b repairs vulnerabilities found in the OS or in applications, cutting off the infection route in which a virus exploits a vulnerability to intrude and run on its own. So exactly two measures, a and b, are appropriate as prevention measures, and “ア”, which lists only these two, is the correct answer.
Incorrectイ
a and b are correct, but this option wrongly adds c. Setting a hard disk password in c is a measure against unauthorized access and information leakage: it keeps a third party from reading the contents if the PC or the disk is stolen. While a legitimate user is logged in and using the machine, the disk can still be read and written, so it has no effect on stopping a virus from getting in.
Incorrectウ
a is correct, but this option drops b, which is also a prevention measure, and includes d instead, so it is wrong. Encrypting files in d aims at confidentiality: even if a file falls into a third party's hands, its contents cannot be read. Even with encryption, a virus still gets into the PC and runs, and an encrypted file itself can be infected or can be destroyed or carried off while still encrypted, so encryption does not prevent infection.
Incorrectエ
b is correct, but this option lacks a, installing anti-virus software, which is the most basic prevention measure, and it also includes c, which has nothing to do with preventing infection. The question asks for all and only the appropriate items, so leaving out an appropriate item is not allowed either.
ここがポイント
- Measures for preventing virus infection rest on two pillars: anti-virus software (detection and removal) and applying security patches (eliminating vulnerabilities). Both assume that pattern files and fix modules are kept up to date.
- Setting passwords and encrypting are means of protecting confidentiality, one of the three elements of information security, and they are countermeasures against unauthorized access and information leakage. Their purpose is different, so they do not count as measures for preventing virus infection. What is tested here is whether you can sort measures by their purpose.
用語