Amazon Web Services Updated SCS-C03 Exam Questions and Answers by charlie

Amazon S3 Lifecycle rules provide a native, fully managed mechanism to automatically transition or delete objects based on their age. According to the AWS Certified Security – Specialty Official Study Guide, S3 Lifecycle policies are the recommended and most secure method for enforcing data retention requirements because they operate automatically, consistently, and without custom code.

By configuring a lifecycle rule to delete objects after 45 days, the company ensures that sensitive datasets are retained long enough to support the 30-day model training process while remaining compliant with the data retention policy. Lifecycle rules are enforced by Amazon S3 itself and apply uniformly to all objects in the bucket or to objects that match specific prefixes or tags.

Option B and Option C introduce unnecessary operational complexity and risk by relying on custom Lambda code and scheduling. These approaches are more error-prone, harder to audit, and less reliable than a built-in S3 capability. Option D is incorrect because S3 Intelligent-Tiering manages storage cost optimization and does not delete data.

AWS documentation explicitly states that S3 Lifecycle rules are the standard control for enforcing retention and deletion policies, particularly for sensitive data stored at scale.

AWS Certified Security – Specialty Official Study Guide

Amazon S3 Lifecycle Configuration Documentation

AWS Data Protection Best Practices

Amazon GuardDuty provides continuous monitoring for anomalous and malicious network activity by analyzing VPC Flow Logs, DNS logs, and CloudTrail events. Enabling GuardDuty across accounts requires minimal configuration and immediately satisfies the requirement to monitor endpoints for anomalous network traffic, as described in the AWS Certified Security – Specialty Study Guide.

Encrypting data in transit for applications behind Elastic Load Balancing is most efficiently achieved by using AWS Certificate Manager (ACM). ACM provisions and manages TLS certificates automatically, and integrating ACM with ELB enables encrypted communication without manual certificate management.

For encryption at rest in Amazon S3, AWS best practices recommend enforcing server-side encryption using AWS KMS. An S3 bucket policy that denies PutObject requests unless the x-amz-server-side-encryption condition is present ensures that all uploaded objects are encrypted at rest using KMS-managed keys. This provides strong encryption guarantees with minimal operational effort.

Option A is unnecessary because Amazon Inspector focuses on vulnerability assessment, not encryption or network anomaly detection. Option C adds network complexity and is not required to meet the stated requirements. Option E is incorrect because x-amz-meta-side-encryption is not a valid enforcement mechanism.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon GuardDuty Threat Detection

AWS Certificate Manager and ELB Integration

Amazon S3 Encryption Best Practices

AWS WAF provides managed and custom rules that can immediately mitigate common web exploits such as SQL injection without modifying application code. According to AWS Certified Security – Specialty documentation, placing AWS WAF in front of an Application Load Balancer is a recommended rapid-response control for legacy applications with known vulnerabilities.

Creating an ALB in front of the existing EC2 instances allows seamless traffic migration. AWS WAF SQL injection rules can be deployed and tested without downtime. Updating Route 53 to point to the ALB preserves normal operations. Restricting EC2 security groups afterward prevents bypassing the WAF.

Option B introduces CloudFront changes and single-origin testing, increasing complexity. Option C cannot be completed within 24 hours and risks downtime. Option D is invalid because AWS WAF cannot be attached directly to EC2 instances.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS WAF Web ACL Architecture

AWS Application Load Balancer Security

Amazon GuardDuty Exfiltration:S3/AnomalousBehavior findings indicate that S3 data access patterns are consistent with data exfiltration. In this scenario, the attacker is using temporary credentials obtained from an EC2 instance profile, which are issued by AWS Security Token Service (STS).

According to AWS Certified Security – Specialty documentation, the fastest and most targeted remediation is to revoke the temporary session credentials associated with the compromised instance profile. This can be accomplished by removing or modifying the IAM role permissions, detaching the instance profile, or stopping the instance, which immediately invalidates the temporary credentials and prevents further S3 access.

Option B may limit outbound traffic but does not invalidate already issued credentials. Option C is a detection and classification service and does not prevent active exfiltration. Option D would block all access to the bucket, including legitimate access, and is considered overly disruptive for incident containment.

AWS incident response best practices emphasize credential revocation as the first containment step when compromise of temporary credentials is confirmed.

AWS Certified Security – Specialty Official Study Guide

Amazon GuardDuty User Guide – S3 Protection

AWS STS and IAM Role Security Documentation

AWS Incident Response Best Practices