A security administrator is setting up a new AWS account. The security administrator wants to secure the data that a company stores in an Amazon S3…

Configuring the Amazon S3 Block Public Access feature at the AWS account level is the most effective and efficient method to meet the requirements. This single action establishes a security baseline that applies to all existing and future S3 buckets within the account. It prevents the application of public bucket policies or Access Control Lists (ACLs), directly mitigating the risk of unintended data exposure from misconfigurations. This "set-it-and-forget-it" approach provides a broad, preventative control with the least possible operational overhead, as it does not require configuration on a per-bucket or per-object basis.

B. Configure the S3 Block Public Access feature for all objects that are in the bucket.

This is incorrect because the Block Public Access feature is configured at the bucket or account level, not on individual objects.

C. Deactivate ACLs for objects that are in the bucket.

While disabling ACLs (using S3 Object Ownership) is a best practice for simplifying access management, it must be done per bucket and does not prevent a misconfigured bucket policy from making the bucket public.

D. Use AWS PrivateLink for Amazon S3 to access the bucket.

AWS PrivateLink secures the network path to S3 from a VPC but does not prevent the S3 bucket or its objects from being configured for public access.

1. AWS Documentation - Amazon S3 User Guide: "Blocking public access to your Amazon S3 storage". This guide states, "Amazon S3 Block Public Access provides settings for access points, buckets, and accounts to help you manage public access to Amazon S3 resources... We recommend that you turn on Block Public Access for all your accounts and buckets unless you know that you need public access." This confirms that the account-level setting is the most comprehensive and recommended approach.

Source: Amazon S3 User Guide, Section: "Blocking public access to your Amazon S3 storage".

2. AWS Documentation - Amazon S3 User Guide: "How S3 Block Public Access works". The documentation details the four settings that can be applied at the account or bucket level. Applying them at the account level ensures that "no bucket in your account can be made public," which directly addresses the question's requirements with minimal effort.

Source: Amazon S3 User Guide, Section: "How S3 Block Public Access works".

3. AWS Documentation - Amazon S3 User Guide: "Controlling ownership of objects and disabling ACLs for your bucket". This document explains that disabling ACLs simplifies access control but notes that access is then defined using resource-based policies. This does not inherently prevent a public bucket policy, unlike the Block Public Access feature.

Source: Amazon S3 User Guide, Section: "Controlling ownership of objects and disabling ACLs for your bucket".

4. AWS Documentation - Amazon S3 User Guide: "Accessing S3 using an interface endpoint (AWS PrivateLink)". This guide explains that PrivateLink provides private connectivity to S3. It does not mention anything about preventing public access configurations on the S3 bucket itself, as it is a network-level control.

Source: Amazon S3 User Guide, Section: "Accessing S3 using an interface endpoint (AWS PrivateLink)".