- A
Isolate the source host from the network to prevent further communication.
Isolating the host stops the malicious activity and prevents lateral movement.
- B
Check the host's web browsing history for suspicious websites.
Why wrong: This action is less immediate and can be done after containment.
- C
Immediately block the destination IP on the firewall.
Why wrong: Blocking the destination IP may disrupt the attack but does not address the compromised host. Isolation is more urgent.
- D
Ignore the alert because the traffic is encrypted over port 443.
Why wrong: Encryption does not mean the traffic is safe; Zeus can use HTTPS for command and control.
Question 381 of 1,000
200-201 Security Monitoring Practice Question
This 200-201 practice question tests your understanding of security monitoring. 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 receives an IDS alert with signature name 'ET TROJAN Win32.Zeus Checkin' and severity 'high'. The alert shows source IP 192.168.1.50 and destination IP 198.51.100.20 on port 443. Which action should the analyst take FIRST?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"first"Why it matters: Order matters here. You are being tested on which action comes before the others — not which action is generally useful.
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
✓
Isolate the source host from the network to prevent further communication.
The alert indicates a high-severity Zeus Trojan check-in, which is a known malware communicating with a command-and-control (C2) server. The first priority is to contain the threat by isolating the source host (192.168.1.50) to prevent further data exfiltration or lateral movement. Even though the traffic is encrypted over port 443 (HTTPS), the signature confirms malicious activity, so immediate isolation is the correct initial response per incident response best practices.
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.
- ✓
Isolate the source host from the network to prevent further communication.
Why this is correct
Isolating the host stops the malicious activity and prevents lateral movement.
Clue confirmation
The clue word "first" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Check the host's web browsing history for suspicious websites.
Why it's wrong here
This action is less immediate and can be done after containment.
- ✗
Immediately block the destination IP on the firewall.
Why it's wrong here
Blocking the destination IP may disrupt the attack but does not address the compromised host. Isolation is more urgent.
- ✗
Ignore the alert because the traffic is encrypted over port 443.
Why it's wrong here
Encryption does not mean the traffic is safe; Zeus can use HTTPS for command and control.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the principle that containment (isolating the host) takes precedence over blocking external IPs or performing forensic analysis, and that encryption does not invalidate IDS alerts because signatures can detect malicious patterns in metadata or handshake characteristics.
Trap categories for this question
Command / output trap
Encryption does not mean the traffic is safe; Zeus can use HTTPS for command and control.
Detailed technical explanation
How to think about this question
Zeus (Zbot) uses a modular architecture where the check-in phase involves sending system information to the C2 via HTTPS, often using a unique SSL/TLS fingerprint (JA3 hash) that IDS/IPS can match. The 'ET TROJAN Win32.Zeus Checkin' signature from Emerging Threats likely relies on such fingerprinting or HTTP headers within the TLS handshake, not decrypted content. In a real-world scenario, isolating the host via network access control (NAC) or disabling its switch port stops the C2 channel immediately, while blocking the IP alone is ineffective if the malware uses domain generation algorithms (DGAs) to switch C2 servers.
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.
TExam Day Tips
- 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 200-201 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.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Security Monitoring — study guide chapter
Learn the concepts, then practise the questions
- →
Security Monitoring practice questions
Targeted practice on this topic area only
- →
All 200-201 questions
1,000 questions across all exam domains
- →
Cisco CyberOps Associate 200-201 study guide
Full concept coverage aligned to exam objectives
- →
200-201 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 200-201 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Security Monitoring practice questions
Practise 200-201 questions linked to Security Monitoring.
Network Intrusion Analysis practice questions
Practise 200-201 questions linked to Network Intrusion Analysis.
Security Policies and Procedures practice questions
Practise 200-201 questions linked to Security Policies and Procedures.
Host-Based Analysis practice questions
Practise 200-201 questions linked to Host-Based Analysis.
Security Concepts practice questions
Practise 200-201 questions linked to Security Concepts.
200-201 fundamentals practice questions
Practise 200-201 questions linked to 200-201 fundamentals.
200-201 scenario practice questions
Practise 200-201 questions linked to 200-201 scenario.
200-201 troubleshooting practice questions
Practise 200-201 questions linked to 200-201 troubleshooting.
Practice this exam
Start a free 200-201 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this 200-201 question test?
Security Monitoring — This question tests Security Monitoring — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Isolate the source host from the network to prevent further communication. — The alert indicates a high-severity Zeus Trojan check-in, which is a known malware communicating with a command-and-control (C2) server. The first priority is to contain the threat by isolating the source host (192.168.1.50) to prevent further data exfiltration or lateral movement. Even though the traffic is encrypted over port 443 (HTTPS), the signature confirms malicious activity, so immediate isolation is the correct initial response per incident response best practices.
What should I do if I get this 200-201 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "first". Order matters here. You are being tested on which action comes before the others — not which action is generally useful.
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 →
Last reviewed: Jul 4, 2026
This 200-201 practice question is part of Courseiva's free Cisco 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 200-201 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.