mediumMultiple ChoiceObjective-mapped
ISC2 CC A security analyst observes these SSH logs Practice Question
Exhibit
Refer to the exhibit. --- $ cat /var/log/syslog | grep "sshd" Apr 10 03:22:15 server1 sshd[12345]: Failed password for root from 10.0.0.99 port 22 ssh2 Apr 10 03:22:17 server1 sshd[12346]: Failed password for root from 10.0.0.99 port 22 ssh2 Apr 10 03:22:19 server1 sshd[12347]: Failed password for admin from 10.0.0.99 port 22 ssh2 Apr 10 03:22:21 server1 sshd[12348]: Failed password for admin from 10.0.0.99 port 22 ssh2 ---
A security analyst observes these SSH logs. What is the MOST likely attack?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Brute force attack on SSH service
Repeated failed login attempts from the same IP indicate a brute force attack on the SSH service. Option B is incorrect because session hijacking involves taking over an existing authenticated session, not repeated login attempts. Option C is incorrect because phishing is a social engineering attack, not evident in these logs. Option D is incorrect because a denial of service attack would typically show a flood of traffic, not repeated authentication attempts.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Brute force attack on SSH service
Why this is correct
Multiple failed attempts from a single IP.
- ✗
Session hijacking via SSH
Why it's wrong here
Session hijacking would not produce failed password logs.
- ✗
Phishing attack targeting root and admin accounts
Why it's wrong here
Phishing would not appear in SSH logs.
- ✗
Denial of service attack on port 22
Why it's wrong here
DoS would flood connections, not just failed logins.
Go deeper
Related to this question
Learn chapter
Introduction to Security Principles
Key term
Authentication
Authentication is the process of verifying that someone or something is who or what it claims to be before granting access to a system or resource.
Key term
Social engineering
Social engineering is the psychological manipulation of people into divulging confidential information or performing actions that compromise security.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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