Tutorial / Cram Notes

The functionality of AWS services can be audited through logs and monitoring tools provided by AWS. When an event does not trigger an alert, start by inspecting services such as Amazon CloudWatch and AWS CloudTrail logs, which can offer insights into API calls and resource modifications.

CloudTrail

provides a record of actions taken by a user, role, or AWS service. Reviewing CloudTrail logs can reveal who or what made changes to your resources and when those changes were made. To analyze CloudTrail logs, you can use queries on the Event history or leverage Amazon Athena for advanced analysis on log data stored in S3.

CloudWatch

monitors your AWS resources and the applications you run on AWS. Ensure that CloudWatch alarms are properly set up for metrics that reflect the health and performance of your services. Analyzing CloudWatch metrics post-event can help determine if there were any abnormalities leading up to the incident.


SELECT *
FROM “cloudtrail_logs”
WHERE eventTime BETWEEN ‘2023-04-01T00:00:00Z’ AND ‘2023-04-02T00:00:00Z’;

Permissions

Permissions in AWS are managed using Identity and Access Management (IAM). After an event, it is crucial to audit IAM roles, policies, and permissions to ensure they adhere to the principle of least privilege.

IAM Roles and Policies

Review the IAM roles involved in the incident and their associated policies. Check for any overly permissive policies that may have allowed unwanted actions.

Resource-Based Policies

Some AWS services allow you to attach policies directly to resources (like S3 bucket policies or Lambda permissions). Ensure these policies do not grant excessive permissions which could lead to security vulnerabilities.

Service Control Policies (SCPs)

If you are using AWS Organizations, SCPs offer central control over the maximum available permissions for all accounts in your organization. Review the SCPs to ensure they were not relaxed or misconfigured.

Configuration of Resources

The configuration of resources can significantly affect the visibility and alerting of events. Misconfigurations are a common cause of security incidents in the cloud.

AWS Config is a service that enables you to assess, audit, and evaluate the configurations of your AWS resources. This service can be used to review the configurations and changes over time, which might have led to the event.

Security Groups and Network ACLs: Review the configuration of your VPC’s Security Groups and Network ACLs to ensure that they have not been relaxed to leave your resources exposed to unwanted traffic.

Resource Type Configuration Check Example Concern
EC2 Instances Security Groups Unwanted inbound ports open
S3 Buckets Bucket Policies, Public Access Block Publicly accessible buckets
RDS Databases Encryption, Public Accessibility Databases not encrypted

When analyzing configuration, tools like AWS Config Rules can ensure that specific compliance checks are in place, continuously evaluating your AWS resources for your desired configuration settings.

In conclusion, after an event with no visibility or alerting, it is essential to meticulously analyze service functionality, permissions, and resource configurations within your AWS environment. This involves diving deep into logs, monitoring tools, IAM configurations, and the AWS Config service amongst others. By carefully auditing these aspects, you can identify the root cause, mitigate the risks, and enhance your AWS environment’s security and compliance posture.

Practice Test with Explanation

True or False: AWS CloudTrail provides a history of AWS API calls for your account.

  • (A) True
  • (B) False

Answer: A

Explanation: AWS CloudTrail records AWS API calls for your account and delivers log files for audit and review.

After an event with no visibility, which AWS service can be used to retrospectively analyze network traffic flow?

  • (A) AWS WAF
  • (B) AWS Shield
  • (C) VPC Flow Logs
  • (D) Amazon CloudWatch

Answer: C

Explanation: VPC Flow Logs enables you to capture information about the IP traffic going to and from network interfaces in your VPC for retrospective analysis.

Which AWS service should you check first if you receive no billing alerts for unexpected high usage?

  • (A) Amazon CloudWatch
  • (B) AWS Budgets
  • (C) AWS Cost and Usage Report
  • (D) AWS Cost Explorer

Answer: B

Explanation: AWS Budgets is the service responsible for alerting you when your usage exceeds the thresholds you define.

True or False: AWS Config provides detailed insights and auditing capabilities for your AWS resource configurations.

  • (A) True
  • (B) False

Answer: A

Explanation: AWS Config is a service that enables you to assess, audit, and evaluate the configurations of your AWS resources.

True or False: Amazon GuardDuty is a threat detection service that continuously monitors for malicious activity and unauthorized behavior.

  • (A) True
  • (B) False

Answer: A

Explanation: Amazon GuardDuty monitors for suspicious activity and unauthorized behavior using integrated threat intelligence, machine learning, and anomaly detection.

Which of the following permissions-related features allows you to validate IAM policies against best practices?

  • (A) IAM Access Analyzer
  • (B) AWS Trusted Advisor
  • (C) AWS Organizations SCPs
  • (D) AWS IAM Credential Report

Answer: A

Explanation: IAM Access Analyzer helps you validate your policies against AWS best practices to ensure least privilege permissions.

In the case of unexpected access to an S3 bucket, which AWS service should be checked to ensure it only allows traffic from specific IP addresses?

  • (A) Amazon CloudWatch
  • (B) S3 Bucket Policy
  • (C) AWS Shield Advanced
  • (D) AWS WAF

Answer: B

Explanation: An S3 Bucket Policy can be set to restrict access to the bucket from specific IP addresses.

True or False: AWS Security Hub cannot aggregate findings from other AWS security services.

  • (A) True
  • (B) False

Answer: B

Explanation: AWS Security Hub is designed to aggregate and prioritize findings from other AWS security services like GuardDuty, Inspector, and Macie.

Which service can be used to ensure that all your EC2 instances are within your compliance requirements after an event?

  • (A) AWS Config
  • (B) AWS System Manager
  • (C) AWS Inspector
  • (D) AWS CloudTrail

Answer: A

Explanation: AWS Config allows you to check the compliance of your EC2 instances against desired configurations.

If an Amazon EC2 instance was unexpectedly launched, which AWS feature can help to trace who initiated the launch?

  • (A) AWS IAM Access Advisor
  • (B) Amazon VPC Flow Logs
  • (C) AWS CloudTrail
  • (D) AWS Config

Answer: C

Explanation: AWS CloudTrail logs user and API activity within your AWS environment and can identify who initiated the launch of an EC2 instance.

True or False: AWS Identity and Access Management (IAM) roles for AWS Lambda enable the function to interact with other AWS services.

  • (A) True
  • (B) False

Answer: A

Explanation: AWS Lambda uses IAM roles to obtain the necessary permissions to interact with other AWS services.

When an AWS resource is shared with an external account, which of the following should you review to analyze permissions?

  • (A) AWS Organization’s Service Control Policies (SCPs)
  • (B) IAM Roles and Resource-based Policies
  • (C) AWS CloudTrail event history
  • (D) All of the above

Answer: D

Explanation: All mentioned options can play a role in analyzing permissions when resources are shared with external accounts. SCPs can limit actions across all accounts in an organization, IAM roles and resource-based policies can grant access to resources, and CloudTrail provides historical event data.

Interview Questions

How does AWS CloudTrail support the analysis of events that did not provide visibility or alerting?

AWS CloudTrail provides a history of AWS API calls for an account, including calls made through the AWS Management Console, AWS SDKs, command line tools, and other AWS services. This enables you to perform a retrospective analysis of events that did not trigger an alert by searching for unusual or unauthorized API activity that may have led to the event.

Explain how you would use AWS Config to assess the compliance of resource configurations after an incident with no visibility or alerting.

AWS Config allows continuous monitoring and recording of AWS resource configurations, enabling you to audit configurations and evaluate changes over time. After an incident, you can use AWS Config to review the configuration history and determine if any non-compliant resources contributed to the lack of visibility or alerting.

Describe how IAM policies can be analyzed post-event to ensure the principle of least privilege is being followed.

Post-event, IAM policies can be analyzed using IAM Access Analyzer to identify any policies granting excessively broad permissions that do not adhere to the principle of least privilege. IAM Access Analyzer helps analyze resource-sharing and access permissions, highlighting potential privilege escalation issues or unintended resource access.

What role does Amazon CloudWatch play in the post-event analysis of an AWS environment?

Amazon CloudWatch collects and monitors metrics, logs, and events, which allows you to set up alarms for anomalous behavior indicative of security incidents. After an event, CloudWatch logs and metrics can be used for a detailed analysis of the system’s performance and operational health at the time of the incident, helping identify gaps in monitoring that led to the absence of visibility or alerting.

How could you leverage Amazon Inspector to reinforce security after an undisclosed event has occurred?

After an undisclosed event, an automated security assessment can be performed using Amazon Inspector, which assesses applications for exposure, vulnerabilities, and deviations from best practices. By running Inspector assessments, you can identify security issues like network accessibility and common vulnerabilities that could have contributed to the lack of alerting.

Can you explain how to use AWS Security Hub to manage security alerts efficiently?

AWS Security Hub aggregates, organizes, and prioritizes security alerts – or findings – from AWS services such as Amazon GuardDuty, Amazon Inspector, and Amazon Macie. To manage alerts efficiently, you can centralize and analyze findings, and leverage the automatic compliance checks to assess against the standards relevant for the specific type of event, improving your response and investigation capabilities.

What steps would you take using AWS service-linked roles to review resource access permissions after a silent event?

After a silent event, I would review the service-linked roles to ensure that they have the minimum required permissions. I would validate that these roles are only used by the intended AWS services and do not have any additional permissions attached that could have led to the event occurring undetected.

How can AWS Trusted Advisor assist in the post-event analysis regarding resource optimization and security?

AWS Trusted Advisor analyzes your AWS environment and provides recommended actions for optimizing resources and increasing security posture. Post-event, Trusted Advisor can help identify poorly configured and unoptimized resources that may have contributed to the incident, and provide guidance on how to remediate these issues.

In the context of resource configuration, how would you employ AWS Systems Manager to mitigate the risk of future undetected events?

AWS Systems Manager can help manage and automate the configuration of your AWS resources at scale. You can use it to ensure consistent resource configuration by applying desired state configurations with State Manager, automating patching with Patch Manager, and managing secrets to reduce the risk of misconfiguration leading to undetected events.

If an event occurred without visibility or alerting due to misconfigured network access control, how would you use AWS Network Firewall or AWS WAF for post-event analysis?

I would review the logs from AWS Network Firewall or AWS WAF, which can provide detailed information on traffic flow and access attempts. These logs can be analyzed to identify any unchecked pathways or requests that bypassed the alerting mechanisms, aiding in understanding and mitigating the issues that led to the silent event.

What process would you use with Amazon VPC flow logs to diagnose issues after an event that was not alerted on?

Amazon VPC flow logs capture network flow information for VPC, which can be used for post-event diagnostics. I would analyze the VPC flow log data to track the requests made to and from the VPC around the time of the event, identifying potential unauthorized network activity or data exfiltration that went unnoticed.

Describe how you would utilize AWS Lambda and Amazon EventBridge to enhance automated response to incidences that lack visibility.

To enhance automated response, I would use AWS Lambda to create custom functions that can be triggered by Amazon EventBridge. EventBridge can be configured to detect patterns in AWS service events, invoking Lambda functions to respond automatically when specific conditions are met. This setup can help fill gaps in monitoring, providing a programmatic way to handle incidents that might otherwise not generate alerts.

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Kasper Jørgensen
5 months ago

Great post! Analyzing AWS services after an event is crucial for maintaining security.

Christin Gaiser
6 months ago

Does anyone have a strategy for automating these analyses?

Emilie Hansen
5 months ago

Thanks for this detailed tutorial!

Pranay Shroff
6 months ago

What tools can I use to visualize permissions and configurations better?

Yana Garmash
6 months ago

This was very informative. Appreciate it!

Adrián Vargas
5 months ago

Is there a way to backtrack and identify which service caused the event?

Kvitoslava Zelinska
6 months ago

This post lacked depth on specific AWS service permissions.

Bratislav Polić
5 months ago

I use GuardDuty for threat detection. It works well for post-event analysis.

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