A holding company runs 42 AWS accounts inside one AWS Organizations organization. Seven business units own those accounts outright, and the operating agreement signed when the units were acquired guarantees that every unit keeps the ability to use any AWS service in any AWS Region without central approval. A new group security policy now requires the central security team to learn within minutes whenever an account exposes a resource publicly, leaves a new volume unencrypted, or drifts from the company baseline, and to keep one searchable record of those findings for the annual audit. Today the security team receives nothing. Each business unit runs its own detective tooling and mails a summary once a quarter. The security team has four engineers, and the chief information security officer has ruled out building or maintaining collection code inside 42 member accounts. Which solution will meet these requirements with the LEAST operational overhead?
Pick an answer to reveal the explanation.
Why this is correct
Correct answer: Delegate AWS Security Hub and Amazon GuardDuty administration to a security account, turn on organization wide enablement for new accounts, and route findings to the team through Amazon EventBridge. Detection and aggregation are the only class of control that survives an agreement promising every unit unrestricted use of AWS. Read the constraint before the requirement list. The acquisition agreement guarantees that each unit may use any service in any Region without central approval. That one sentence removes every preventive instrument from consideration, because service control policies, Control Tower preventive controls and permissions boundaries all work by refusing API calls. What the new policy actually asks for is awareness in minutes plus a durable, searchable record, and that is an aggregation problem rather than a governance problem. Security Hub and GuardDuty are both built for exactly this shape. Each supports a delegated administrator account nominated once from the management account, and after delegation the administrator can enable the service across the whole organization and switch on automatic enablement so that accounts created later are covered with nobody touching them. GuardDuty produces threat findings from CloudTrail, DNS and VPC flow telemetry. Security Hub runs the standards checks, normalizes findings from GuardDuty, Amazon Inspector, Amazon Macie and AWS Config into one schema, and holds them centrally with cross-Region aggregation available on top. Every finding is published to the default EventBridge bus in the administrator account, so one rule filtered on severity gives four engineers alerting in minutes with no collection code anywhere. Note the division of labor the exam keeps probing. GuardDuty detects, Security Hub aggregates and scores, and neither prevents anything. That is precisely why the pair fits an organization where prevention is contractually off limits, and it is also why neither of them alone would satisfy the searchable record requirement. One naming point for the exam room: AWS has renamed the aggregation service in its documentation to AWS Security Hub CSPM, while the SAP-C02 exam guide and the exam itself still print AWS Security Hub. A service control policy at the organization root plus a weekly CloudTrail review breaks the operating agreement on its first day, because an SCP is a permission ceiling that denies the very services the business units were promised. It also answers the wrong question. A weekly read of access denied entries is neither within minutes nor a record of resource exposure. A Config rule pack pushed to each account with a Lambda function that emails the security team is technically workable, which is what makes it tempting, but it is the overhead the CISO explicitly ruled out. It means owning a function, a role and an alerting path in 42 accounts, and a mailbox full of messages is not a searchable finding store. An AWS Config aggregator in a security account, reviewed when the annual audit comes round, is the near miss worth studying, because unlike the others it is both central and detective. It loses on timing first. A view that somebody opens once a year is a periodic read rather than awareness within minutes, and an aggregator carries no notification path of its own. It loses on reach second. AWS documents that an aggregator is a read only view into its source accounts and that rules cannot be deployed through it, so every check that would notice a public resource or an unencrypted volume still has to be switched on in all 42 accounts and every Region before the aggregated view holds anything at all. Key exam concept: when a stem promises that account owners retain full control, every preventive answer is wrong by construction, and the detective options that remain are then separated by how a finding travels. Delegated administration with organization wide automatic enablement is what gives an AWS security service reach into accounts the central team does not govern, and a push onto an event bus is what turns those findings into alerting within minutes, which an aggregated view a human opens later never does.