IPA IP 2023 Question 73
A question IPA Japan published in 令和5年度 ITパスポート試験 公開問題 問73, translated into English. ITPEC is based on the same exams.
Same question on ITPEC: Apr 2024 Q45
When an attacker makes an unauthorized intrusion into a computer, the attacker sometimes changes a program or settings in the computer in order to make further intrusions into the computer easier. Which of the following is the most appropriate term to express the method used by the attacker for further intrusions into the computer?
Explanation
Backdoor — a hidden way back into the computer that the intruder sets up after the first break-in.
Once inside, an attacker often changes programs or settings: installs a program listening on a hidden port, adds an account of their own, or alters the login program, so that later access bypasses the normal authentication and logging. Fixing the vulnerability used for the first intrusion does not close a backdoor, which is why a compromised computer is usually rebuilt from clean media rather than just patched.
Answer (b)
Why not others:
- •(a) Tapping — intercepting (eavesdropping on) communication on a line or network; it reads data in transit and changes nothing in the computer
- •(c) Phishing — deceiving users with fake e-mails and websites into giving away IDs and passwords; it attacks the person, not the computer's programs or settings
- •(d) Port scan — probing a computer's ports to find which services are open; reconnaissance done before an intrusion to look for a way in
Key rule: A backdoor is about persistence: it keeps a way in open after the first intrusion, whereas port scans and phishing are ways of getting in the first time.
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This question comes from the past questions IPA Japan publishes, translated into English by ITPEC Practice. ITPEC Practice is an independent study tool and is not affiliated with IPA or ITPEC. See the original paper (PDF) or Report an issue.