XK0-006 Security Practice Question
A security analyst needs to see a list of failed login attempts on a Linux system. Which command displays this information from the /var/log/btmp log?
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
✓
lastb
lastb shows failed login attempts by reading the /var/log/btmp file. last reads /var/log/wtmp for successful logins, lastlog shows last login per user from /var/log/lastlog, and faillog is an older command that reads from /var/log/faillog.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
lastb
Why this is correct
lastb displays bad login attempts from /var/log/btmp.
- ✗
lastlog
Why it's wrong here
lastlog shows the most recent login for each user.
- ✗
last
Why it's wrong here
last shows successful logins from /var/log/wtmp.
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faillog
Why it's wrong here
faillog is an older utility, not commonly used; lastb is standard.
Go deeper
Related to this question
Learn chapter
Linux Fundamentals and History
Key term
Linux
Linux is an open-source operating system that manages computer hardware and software, widely used in servers, desktops, and embedded systems.
Key term
User
A user is any person, system, or device that interacts with an IT service, resource, or identity system, typically authenticated through credentials and authorized to perform specific actions.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This XK0-006 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the XK0-006 exam.