This SCS-C02 practice question tests your understanding of threat detection and incident response. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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.
A security team wants to detect unauthorized API calls in real time and automatically block the source IP address using network ACLs. Which AWS service should be used for detection?
Amazon GuardDuty
GuardDuty uses machine learning to detect suspicious API activity.
AWS CloudTrail
Why wrong: CloudTrail logs API calls but does not detect threats.
AWS WAF
Why wrong: WAF protects web applications, not API calls.
AWS Config
Why wrong: Config tracks resource configuration changes.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Amazon GuardDuty
Amazon GuardDuty is the correct choice because it is a threat detection service that continuously monitors for malicious activity and unauthorized behavior, including API calls from unusual or known-bad IP addresses. It uses machine learning, anomaly detection, and integrated threat intelligence to generate findings that can trigger automated remediation, such as updating network ACLs via AWS Lambda and Amazon EventBridge. This aligns with the requirement for real-time detection and automated blocking of source IPs.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Amazon GuardDuty
Why this is correct
GuardDuty uses machine learning to detect suspicious API activity.
Related concept
Read the scenario before looking for a memorised answer.
AWS CloudTrail
Why it's wrong here
CloudTrail logs API calls but does not detect threats.
AWS WAF
Why it's wrong here
WAF protects web applications, not API calls.
AWS Config
Why it's wrong here
Config tracks resource configuration changes.
Common exam traps
The trap here is that candidates often confuse AWS CloudTrail's logging capability with real-time threat detection, overlooking that GuardDuty is specifically designed for proactive security monitoring and automated response, while CloudTrail is purely a logging and auditing service.
Detailed technical explanation
GuardDuty integrates with VPC Flow Logs, DNS logs, and CloudTrail management events to detect suspicious patterns, such as an API call from an IP address associated with a known threat actor (e.g., from a threat intelligence feed like Proofpoint or CrowdStrike). Under the hood, GuardDuty uses a combination of rule-based detection and machine learning models to establish baselines for normal API call behavior, enabling it to flag anomalies like a sudden spike in calls from a single IP. In a real-world scenario, a compromised IAM key might be used to make unauthorized API calls from an unexpected geographic region; GuardDuty would generate a finding that can be consumed by EventBridge to invoke a Lambda function that modifies the VPC's network ACL to block the offending IP.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A healthcare organisation deploys an application with a public-facing web tier and a private database tier. The database subnet has no public IP and only accepts connections from the web tier's security group. Questions like this test whether you can design cloud network isolation using VNets/VPCs, subnets, and security group rules.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Threat Detection and Incident Response — study guide chapter
Learn the concepts, then practise the questions
Threat Detection and Incident Response practice questions
Targeted practice on this topic area only
All SCS-C02 questions
1,738 questions across all exam domains
AWS Certified Security Specialty SCS-C02 study guide
Full concept coverage aligned to exam objectives
SCS-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise SCS-C02 questions linked to Threat Detection and Incident Response.
Practise SCS-C02 questions linked to Security Logging and Monitoring.
Practise SCS-C02 questions linked to Identity and Access Management.
Practise SCS-C02 questions linked to Management and Security Governance.
Practise SCS-C02 questions linked to Infrastructure Security.
Practise SCS-C02 questions linked to Data Protection.
Practise SCS-C02 questions linked to SCS-C02 fundamentals.
Practise SCS-C02 questions linked to SCS-C02 scenario.
Practise SCS-C02 questions linked to SCS-C02 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Threat Detection and Incident Response — This question tests Threat Detection and Incident Response — Read the scenario before looking for a memorised answer..
The correct answer is: Amazon GuardDuty — Amazon GuardDuty is the correct choice because it is a threat detection service that continuously monitors for malicious activity and unauthorized behavior, including API calls from unusual or known-bad IP addresses. It uses machine learning, anomaly detection, and integrated threat intelligence to generate findings that can trigger automated remediation, such as updating network ACLs via AWS Lambda and Amazon EventBridge. This aligns with the requirement for real-time detection and automated blocking of source IPs.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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 →
Keep practising
Last reviewed: Jun 24, 2026
This SCS-C02 practice question is part of Courseiva's free Amazon Web Services 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 SCS-C02 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.