Amazon Inspector is an automated security assessment service that helps improve the security and compliance of applications deployed on AWS. Amazon Inspector automatically assesses applications for exposure, vulnerabilities, and deviations from best practices. After performing an assessment, Amazon Inspector produces a detailed list of security findings prioritized by level of severity1. Amazon Inspector can scan the EC2 instances for software vulnerabilities and provide a report of each instance’s patch status. AWS Systems Manager Patch Manager is a capability of AWS Systems Manager that automates the process of patching managed nodes with both security-related updates and other types of updates. Patch Manager uses patch baselines, which include rules for auto-approving patches within days of their release, in addition to optional lists of approved and rejected patches. Patch Manager can patch fleets of Amazon EC2 instances, edge devices, on-premises servers, and virtual machines (VMs) by operating system type2. Patch Manager can patch the EC2 instances on a regular schedule and provide a report of each instance’s patch status. Therefore, the combination of Amazon Inspector and AWS Systems Manager Patch Manager will meet the requirements of the question.
The other options are not valid because:
Amazon Macie is a security service that uses machine learning to automatically discover, classify, and protect sensitive data in AWS. Amazon Macie does not scan the EC2 instances for software vulnerabilities, but rather for data classification and protection3. A cron job is a Linux command for scheduling a task to be executed sometime in the future. A cron job is not a reliable way to patch the EC2 instances on a regular schedule, as it may fail or be interrupted by other processes4.
Amazon GuardDuty is a threat detection service that continuously monitors for malicious activity and unauthorized behavior to protect your AWS accounts and workloads. Amazon GuardDuty does not scan the EC2 instances for software vulnerabilities, but rather for network and API activity anomalies5. AWS Systems Manager Session Manager is a fully managed AWS Systems Manager capability that lets you manage your Amazon EC2 instances, edge devices, on-premises servers, and virtual machines (VMs) through an interactive one-click browser-based shell or the AWS Command Line Interface (AWS CLI). Session Manager does not patch the EC2 instances on a regular schedule, but rather provides secure and auditable node management2.
Amazon Detective is a security service that makes it easy to analyze, investigate, and quickly identify the root cause of potential security issues or suspicious activities. Amazon Detective does not scan the EC2 instances for software vulnerabilities, but rather collects and analyzes data from AWS sources such as Amazon GuardDuty, Amazon VPC Flow Logs, and AWS CloudTrail. Amazon EventBridge is a serverless event bus that makes it easy to connect applications using data from your own applications, integrated Software-as-a-Service (SaaS) applications, and AWS services. EventBridge delivers a stream of real-time data from event sources, such as Zendesk, Datadog, or Pagerduty, and routes that data to targets like AWS Lambda. EventBridge does not patch the EC2 instances on a regular schedule, but rather triggers actions based on events.
References: Amazon Inspector, AWS Systems Manager Patch Manager, Amazon Macie, Cron job, Amazon GuardDuty, [Amazon Detective], [Amazon EventBridge]