問94
頻出度★★★
ランサムウェアの説明として, 適切なものはどれか。
平成31年度 春期 ITパスポート試験 問94
テクノロジ系セキュリティ › 情報セキュリティ
This question's explanation and your answers so far.
解説
問 94
- ア
正解 Ransomware (ransom = the money demanded for a hostage) is malware that secretly encrypts the files on an infected PC to make them unusable and, in effect saying “pay up if you want them back”, demands money in exchange for the decryption key. Choice ア states exactly that it encrypts files to make them unusable and demands money in exchange for the decryption key, which is the very definition of ransomware, so it is the correct answer.
Incorrectイ
Software that illicitly records keyboard input describes a “keylogger”. It is used to steal typed IDs, passwords, and the like; it neither encrypts files nor demands money, so it is not ransomware.
Incorrectウ
Software that makes itself harder to detect by tampering with system logs describes a “rootkit”. Its purpose is to hide the traces of an intrusion and keep lurking; it does not demand money, so it is not ransomware.
Incorrectエ
Software that has the ability to spread its own infection and propagates across networks describes a “worm”. Its defining trait is self-replication and spreading; it does not hold files hostage to demand money, so it is not ransomware.
ここがポイント
- Ransomware is “ransom”-type malware: it encrypts files (or locks the device) to make them unusable and demands money in exchange for restoring access.
- Distinguishing similar malware: keylogger = records input, rootkit = hides traces and lurks, worm = self-replicates and spreads over the network. Tell them apart by their behavior.
用語