Analyzing environments and workloads to determine monitoring requirements

What types of data sources should you consider when setting up monitoring in AWS?

When setting up monitoring in AWS, you should consider data sources such as application logs, CloudTrail logs for API call tracking, VPC Flow Logs for network traffic, Elastic Load Balancer logs for application traffic patterns, and CloudWatch metrics for system health and performance. S3 bucket access logs and AWS Config for resource inventory and changes are also important.

How can Amazon CloudWatch help in identifying potential security threats?

Amazon CloudWatch can be used to collect monitoring data in the form of logs, metrics, and events, which can provide insight into unusual or unauthorized activities. CloudWatch Logs can store log files from EC2 instances, AWS CloudTrail, and other sources. You can set up alarms in CloudWatch to trigger notifications or automated actions if certain thresholds are breached, or certain patterns indicative of a security threat, such as multiple failed login attempts, are detected.

When would you use AWS CloudTrail as opposed to VPC Flow Logs for monitoring purposes?

AWS CloudTrail is best used for monitoring API calls made within your AWS account, providing a history of actions taken by a user, a role, or an AWS service. This is essential for compliance audits and security analysis. VPC Flow Logs, on the other hand, capture information about IP traffic going to and from network interfaces in your VPC, serving as a tool primarily for network monitoring, troubleshooting, and security analysis related to network flows.

For compliance reasons, how should you handle log file retention and what features in AWS can assist with this?

Log files should be retained according to the specific compliance requirements, which often dictate that logs be kept for a certain period, such as 1 year. In AWS, you can use features like Amazon S3 bucket policies for storing logs and setting up data lifecycle management policies to automatically transition logs to less expensive storage classes or delete them after a specified retention period. AWS CloudTrail also supports log file integrity validation, which can ensure log files have not been tampered with.

Describe how you would configure alarms for anomalous behavior in a multi-tier web application hosted in AWS.

To configure alarms for anomalous behavior in a multi-tier web application, I would first identify the normal operational metrics for each tier using Amazon CloudWatch. Then, I would create CloudWatch Alarms based on thresholds that, if breached, could indicate anomalous behavior such as spikes in CPU utilization, unusual latency, or unexpected changes in network traffic patterns. Additionally, I would use CloudWatch Events or AWS Lambda to automate responses to certain alarms, such as triggering an AWS SNS notification or invoking a Lambda function to take remedial action.

What role does Amazon GuardDuty play in monitoring security within AWS environments?

Amazon GuardDuty is a managed threat detection service that continuously monitors for malicious or unauthorized behavior to protect your AWS accounts and workloads. It uses machine learning, anomaly detection, and integrated threat intelligence feeds to identify unexpected and potentially unauthorized or malicious activity, such as unusual API calls or potentially compromised EC2 instances or IAM roles.

Explain how you would monitor and secure an Amazon S3 bucket.

To monitor and secure an Amazon S3 bucket, you would activate server access logging for all requests made to the S3 bucket. Then, you should enable AWS CloudTrail to record actions taken on the S3 bucket. Additionally, you would use AWS Config to track the configuration of the S3 bucket over time, along with S3 Block Public Access to prevent accidental exposure of data. To ensure data is not tampered with or deleted, you could also enable S3 Versioning and MFA Delete.

How can AWS Config help you to monitor compliance with security policies across your AWS infrastructure?

AWS Config allows you to assess, audit, and evaluate the configurations of your AWS resources. It can monitor and record configurations and changes to AWS resources, which makes it possible to review configurations and changes over time for compliance with internal security policies and external regulations. AWS Config Rules can automatically check the configuration of AWS resources recorded by AWS Config to ensure they comply with desired security configurations.

What are the benefits of using AWS Systems Manager for monitoring the security posture of your EC2 instances?

AWS Systems Manager provides a centralized service to manage and automate the maintenance and deployment of EC2 instances. It allows for patch management, enabling you to automate the process of patching managed instances with both security-related and other types of updates. Systems Manager also provides actionable insights into system configurations, operating system state, and software inventory, which can help ensure that instances conform to compliance standards and security best practices. Additionally, Systems Manager can help automate responses to security incidents.

How would you set up an automated workflow to respond to an application instance exhibiting signs of compromise?

To set up an automated workflow for a compromised application instance, I would first use Amazon CloudWatch Alarms to detect signs of a compromise such as unusual CPU patterns or unexpected outbound network traffic. Then, I would configure CloudWatch Events to trigger an AWS Lambda function or Step Functions state machine when an alarm is activated. The AWS Lambda function could isolate the instance by modifying security groups, take a snapshot for later analysis, and replace the instance with a new one from an AMI that has the latest patches and configurations, thus minimizing downtime and potential damage.

How can you use AWS service limits in the context of security monitoring?

Monitoring AWS service limits is important because it helps prevent service disruption and ensures that you don’t exceed the resources you are allowed to use, which could potentially be caused by a misconfiguration or a security incident, such as a DDoS attack or a compromised account launching resources without authorization. AWS Trusted Advisor, a tool that provides real-time guidance, can be used to monitor and alert you if you approach or exceed service limits. This helps maintain the security and performance of your workloads.

Describe a method for detecting and alerting on unauthorized changes to AWS resources.

AWS offers various services that can be used to detect and alert on unauthorized changes, such as AWS Config combined with AWS CloudTrail. AWS Config can record historical configurations and changes to resources, and CloudTrail logs all actions taken in the AWS Management Console, SDKs, command-line tools, and other AWS services. By defining desired configurations and setting up AWS Config rules, you can receive notifications via Amazon SNS when non-compliant changes occur. To further enhance the detection and alerting mechanism, you can integrate these services with Amazon CloudWatch or third-party SIEM solutions to analyze and respond to alerts for unauthorized changes in real-time.