Network Load Balancers operate at Layer 4 and are optimized for extreme performance, ultra-low latency, and handling sudden traffic spikes. According to AWS Certified Security – Specialty documentation, using a TCP listener on an NLB allows TLS traffic to pass through directly to backend containers without termination, preserving true end-to-end encryption.

This approach eliminates the overhead of decrypting and re-encrypting traffic at the load balancer, reducing latency and maximizing throughput. NLBs scale automatically to handle volatile traffic patterns and millions of requests per second.

Application Load Balancers operate at Layer 7 and introduce additional latency due to TLS termination and HTTP processing. Route 53 multivalue routing does not provide load balancing at the transport layer and does not ensure encryption handling.

AWS recommends NLB TCP pass-through for high-performance, end-to-end encrypted container workloads.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Elastic Load Balancing Architecture

Network Load Balancer Performance Characteristics

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 best practices strongly discourage the use of long-term credentials and recommend cross-account IAM roles with temporary credentials for third-party access. According to the AWS Certified Security – Specialty Study Guide, creating an IAM role in the resource-owning account and allowing a trusted external AWS account to assume that role is the recommended pattern for external access.

By creating the IAM role in the company’s production account and specifying the consultant agency’s AWS account as the trusted principal, the company retains full control over permissions. The trust policy can enforce MFA by using the aws:MultiFactorAuthPresent condition key, ensuring that all access requires MFA. Access is granted through AWS Security Token Service (STS), which issues short-lived credentials.

Option A violates the requirement to avoid long-term credentials. Option B is designed for application user authentication, not AWS account access. Option C incorrectly places the role in the consultant’s account, reducing the company’s control over access.

This solution satisfies MFA enforcement, eliminates long-term credentials, and aligns with AWS third-party access best practices.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS IAM Cross-Account Access

AWS STS and MFA Enforcement

Amazon Cognito is a fully managed identity service that providesuser authentication, authorization, and user managementfor web and mobile applications. According to AWS Certified Security – Specialty documentation, Cognito user pools are specifically designed to offload authentication responsibilities from applications while maintaining strong security controls.

By federating authentication with third-party identity providers (such as social IdPs), Cognito eliminates the need for the company to manage user passwords directly. This dramatically reduces password reset requests and customer service overhead, while also improving security throughindustry-standard authentication mechanisms, including MFA and token-based access.

Option A is insecure and incorrect because IAM access keys are not intended for end users. Option B simply relocates password storage and does not reduce operational burden. Option D uses API keys, which are not designed for user authentication and provide no identity verification.

AWS guidance clearly states thatAmazon Cognito is the recommended service for scalable, secure user authentication, especially when reducing password management complexity is a requirement.

AWS Certified Security – Specialty Official Study Guide

Amazon Cognito User Pools Documentation

AWS IAM Security Best Practices

Amazon Cognito identity pools provide temporary AWS credentials by exchanging web identity tokens with AWS STS using AssumeRoleWithWebIdentity. According to AWS Certified Security – Specialty documentation, this is the correct mechanism for granting applications AWS credentials.

User pools authenticate users but do not issue AWS credentials. Identity pools integrate with IAM roles and STS, enabling secure, temporary access to AWS services.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon Cognito Identity Pools

AWS STS Web Identity Federation

Amazon Detective is specifically designed to help security teams investigate and visualize the root cause of security findings. According to AWS Certified Security – Specialty documentation, Detective automatically aggregates and correlates data from GuardDuty, CloudTrail, and VPC Flow Logs to provide interactive visualizations and timelines.

Detective enables investigators to pivot from GuardDuty findings to IAM roles, API calls, network traffic, and resource behavior. This makes it the most efficient tool for understanding how IAM roles were used during suspicious activity.

Amazon Inspector focuses on vulnerability assessment, not behavioral investigation. Security Hub aggregates findings but does not provide deep investigation graphs. Manual analysis with Athena requires significantly more effort.

AWS guidance explicitly recommends Amazon Detective for root cause analysis and visualization of security incidents.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon Detective Investigation Capabilities

AWS Threat Detection and Analysis

AWS Lambda automatically sends function execution logs to Amazon CloudWatch Logs when logging is enabled in the function code. However, this logging capability depends on the Lambda execution role having the appropriate permissions. According to the AWS Certified Security – Specialty Study Guide, the execution role must include permissions such as logs:CreateLogGroup, logs:CreateLogStream, and logs:PutLogEvents.

If these permissions are missing, Lambda cannot create log groups or streams, and no execution logs will appear in CloudWatch Logs—even though the function was successfully invoked. This is the most common reason Lambda logs are unavailable during forensic investigations.

Option B is incorrect because Lambda logs are stored in CloudWatch Logs regardless of whether the invocation source is API Gateway, EventBridge, or another AWS service. Option C is incorrect because CloudWatch Logs does not require direct S3 permissions from the Lambda execution role. Option D is irrelevant because Lambda versions do not affect logging behavior.

AWS documentation emphasizes verifying execution role permissions as a first step when Lambda logs are missing.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS Lambda Execution Roles

Amazon CloudWatch Logs Integration with Lambda

Amazon GuardDuty provides fully managed threat detection across accounts when configured with delegated administration. EKS and RDS protections enable workload-aware detection with minimal setup.

Other solutions require custom pipelines and higher operational overhead.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon GuardDuty Multi-Account Architecture

AWS incident response best practices emphasizerapid containment, credential revocation, and threat detectionto minimize the blast radius of a compromise. According to the AWS Certified Security – Specialty Official Study Guide, when unauthorized resources such as an Amazon S3 bucket hosting malware are discovered, immediate action must be taken to stop further misuse of the account and to prevent recurrence.

Rotating or deleting all AWS access keys (Option D)is a critical containment step. If an IAM user has been compromised, any long-term credentials associated with that user must be revoked immediately to prevent continued unauthorized access. AWS guidance explicitly lists access key rotation or deletion as a first-response action for suspected credential compromise.

Deleting unrecognized or unauthorized resources (Option F)directly removes the malicious infrastructure that is being abused. In this case, deleting the unauthorized S3 bucket immediately stops malware distribution and reduces reputational and compliance impact.

Turning on Amazon GuardDuty (Option B)enables continuous threat detection by analyzing CloudTrail events, VPC Flow Logs, and DNS logs. GuardDuty can identify additional malicious activity, compromised credentials, or persistence mechanisms that the attacker may have established. AWS documentation recommends enabling GuardDuty during or immediately after an incident to detect ongoing or future threats.

Option A does not reduce the impact of the current compromise. Option C is overly disruptive and not recommended; credential rotation should be targeted. Option E is unnecessary because there is no indication that EBS-backed compute resources are involved.

AWS incident response guidance clearly prioritizescredential revocation, malicious resource removal, and threat detectionto minimize consequences.

AWS Certified Security – Specialty Official Study Guide

AWS Incident Response Best Practices

Amazon GuardDuty User Guide

AWS IAM Security Best Practices

AWS Config is purpose-built torecord resource configuration stateand track how that state changes over time. When multiple updates occur close together, AWS Config captures configuration items that represent the resource’scurrent recorded configuration, which is exactly what a compliance engineer needs to evaluate the final (cumulative) state after a burst of changes. AWS Config also integrates directly with compliance evaluation throughConfig rules, which can continuously assess whether the latest configuration meets required standards. This is the most operationally efficient approach because it avoids building custom log filtering, state reconstruction, or timing logic.

CloudTrail and CloudWatch-based approaches (Options A and C) captureAPI events, not authoritative “current configuration state.” Reconstructing the final configuration from a series of API calls can be error-prone, especially when changes are made by different services, via consoles, or through chained automation. CloudTrail is excellent for “who did what and when,” but AWS Config is the service that maintains thelatest configuration snapshotsuitable for compliance posture evaluation.

AWS Cloud Map (Option D) is for service discovery and naming, not compliance configuration history. Therefore, AWS Config is the correct and most efficient solution.