Failed interactive logins such as ConsoleLogin are part of CloudTrail management events, not data events. The most direct, low-overhead design is to stream management events to CloudWatch Logs, then create a metric filter that matches failed ConsoleLogin events (for example, $.eventName = "ConsoleLogin" and $.responseElements.ConsoleLogin = "Failure" or $.errorMessage). That metric is then used as the basis for a CloudWatch alarm. When the alarm threshold (e.g., N failures in a period) is breached, the alarm triggers and sends a notification to the already created SNS topic, which alerts the security team.
Option A follows this recommended pattern: CloudTrail → CloudWatch Logs → Metric Filter → Alarm → SNS. It is fully managed, near real-time, and requires minimal custom logic.
Option B uses Athena with EventBridge to periodically query CloudTrail logs in S3. This introduces more moving parts, more configuration, higher latency, and more operational overhead.
Options C and D incorrectly reference CloudTrail data events and S3 event notifications, which are not the right mechanisms to detect ConsoleLogin failures. Console logins are not S3 events, and using data events would miss these management actions.
Therefore, Option A is the correct and simplest solution.
