Use Amazon GuardDuty to monitor S3 bucket policies Create an automatic remediation action rule that uses an AWS Lambda function to remediate any change that makes the objects public

Use AWS Trusted Advisor to find publicly accessible S3 Dockets Configure email notifications In Trusted Advisor when a change is detected manually change the S3 bucket policy if it allows public access

Use AWS Resource Access Manager to find publicly accessible S3 buckets Use Amazon Simple Notification Service (Amazon SNS) to invoke an AWS Lambda function when a change it detected. Deploy a Lambda function that programmatically remediates the change.

Use the S3 Block Public Access feature on the account level. Use AWS Organizations to create a service control policy (SCP) that prevents IAM users from changing the setting Apply tie SCP to tie account