The answer is that the analyst is most likely trying to determine the IP addresses with the most failed SSH login attempts. This command performs a Linux auth.log brute force analysis by filtering for 'Failed password' entries, extracting the timestamp, username, and source IP (fields $1, $2, $3, $9, $11), then sorting and counting unique occurrences with `uniq -c`. The resulting output directly reveals which remote IPs are hammering the server most aggressively, a classic indicator of a brute-force attack in progress. On the CHFI exam, this tests your ability to interpret common forensic command chains for incident response, specifically parsing authentication logs to identify attack sources. A common trap is confusing `uniq -c` with a simple sort—remember that `uniq -c` counts consecutive duplicates, so the preceding `sort` is essential to aggregate all identical IPs. For a quick memory tip: think of the pipeline as "grep for bad passwords, grab the IP, sort them together, then count the crowd."
CHFI OS and Network Forensics Practice Question
This CHFI practice question tests your understanding of os and network forensics. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
An analyst is examining a Linux server and issues the command: cat /var/log/auth.log | grep 'Failed password' | awk '{print $1,$2,$3,$9,$11}' | sort | uniq -c. What is the analyst most likely trying to determine?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The IP addresses with the most failed SSH login attempts
The command extracts timestamps, usernames, and IP addresses from failed SSH login attempts, then counts unique occurrences. This identifies the most frequent source of brute‑force attempts.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
The list of all sudo commands executed
Why it's wrong here
Sudo commands are logged in auth.log but not with 'Failed password'.
✗
The number of distinct users who successfully logged in
Why it's wrong here
The filter is 'Failed password', so only failed attempts are processed.
✓
The IP addresses with the most failed SSH login attempts
Why this is correct
Correct. It counts failed attempts grouping by date, user, and IP, showing top attackers.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
The total number of successful logins
Why it's wrong here
Successful logins are not filtered; the command explicitly looks for 'Failed password'.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Trap categories for this question
Command / output trap
Sudo commands are logged in auth.log but not with 'Failed password'.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the CHFI exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this CHFI question in full detail.
Identify which CHFI exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
OS and Network Forensics — This question tests OS and Network Forensics — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The IP addresses with the most failed SSH login attempts — The command extracts timestamps, usernames, and IP addresses from failed SSH login attempts, then counts unique occurrences. This identifies the most frequent source of brute‑force attempts.
What should I do if I get this CHFI question wrong?
Identify which CHFI exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. During a Linux forensic investigation, an analyst examines the file /var/log/auth.log and finds repeated entries with 'Failed password for root from 192.168.1.200 port 22 ssh2'. Which TWO conclusions can the analyst draw from this evidence?
medium
A.The source IP 192.168.1.200 belongs to a local subnet
✓ B.The system is experiencing a brute-force attack on SSH
✓ C.The SSH service is enabled and listening on port 22
D.The attacker attempted to exploit a vulnerability in the SSH version
E.An unauthorized user successfully logged in as root
Why B: The log shows failed SSH login attempts for root from a specific IP, indicating a brute-force attack on SSH. The source IP is remote (not localhost). The attempts are unsuccessful (failed).
Last reviewed: Jun 21, 2026
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This CHFI practice question is part of Courseiva's free EC-Council 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 CHFI exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.