March 10, 2026: This post has been updated to note that Amazon Q Detector Library describes the detectors used during code reviews to identify security and quality issues in code.

Enterprise customers face an unprecedented security landscape where sophisticated cyber threats use artificial intelligence to identify vulnerabilities, automate attacks, and evade detection at machine speed. Traditional perimeter-based security models are insufficient when adversaries can analyze millions of attack vectors in seconds and exploit zero-day vulnerabilities before patches are available.

The distributed nature of serverless architectures compounds this challenge—while microservices offer agility and scalability, they significantly expand the attack surface where each API endpoint, function invocation, and data store becomes a potential entry point, and a single misconfigured component can provide attackers the foothold needed for lateral movement. Organizations must simultaneously navigate complex regulatory environments where compliance frameworks like GDPR, HIPAA, PCI-DSS, and SOC 2 demand robust security controls and comprehensive audit trails, while the velocity of software development creates tension between security and innovation, requiring architectures that are both comprehensive and automated to enable secure deployment without sacrificing speed.

The challenge is multifaceted:

• Expanded attack surface: Multiple entry points across distributed services requiring protection against distributed denial of service (DDoS) attacks, injection vulnerabilities, and unauthorized access
• Identity and access complexity: Managing authentication and authorization across numerous microservices and service-to-service communications
• Data protection requirements: Encrypting sensitive data in transit and at rest while securely storing and rotating credentials without compromising performance
• Compliance and data protection: Meeting regulatory requirements through comprehensive audit trails and continuous monitoring in distributed environments
• Network isolation challenges: Implementing controlled communication paths without exposing resources to the public internet
• AI-powered threats: Defending against attackers who use AI to automate reconnaissance, adapt attacks in real-time, and identify vulnerabilities at machine speed

The solution lies in defense-in-depth—a layered security approach where multiple independent controls work together to protect your application.

This article demonstrates how to implement a comprehensive AI-powered defense-in-depth security architecture for serverless microservices on Amazon Web Services (AWS). By layering security controls at each tier of your application, this architecture creates a resilient system where no single point of failure compromises your entire infrastructure, designed so that if one layer is compromised, additional controls help limit the impact and contain the incident while incorporating AI and machine learning services throughout to help organizations address and respond to AI-powered threats with AI-powered defenses.

Architecture overview: A journey through security layers

Let’s trace a user request from the public internet through our secured serverless architecture, examining each security layer and the AWS services that protect it. This implementation deploys security controls at seven distinct layers with continuous monitoring and AI-powered threat detection throughout, where each layer provides specific capabilities that work together to create a comprehensive defense-in-depth strategy:

• Layer 1 blocks malicious traffic before it reaches your application
• Layer 2 verifies user identity and enforces access policies
• Layer 3 encrypts communications and manages API access
• Layer 4 isolates resources in private networks
• Layer 5 secures compute execution environments
• Layer 6 protects credentials and sensitive configuration
• Layer 7 encrypts data at rest and controls data access
• Continuous monitoring detects threats across layers using AI-powered analysis

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Figure 1: Architecture diagram

Layer 1: Edge protection

Before requests reach your application, they traverse the public internet where attackers launch volumetric DDoS attacks, SQL injection, cross-site scripting (XSS), and other web exploits. AWS observed and mitigated thousands of distributed denial of service (DDoS) attacks in 2024, with one exceeding 2.3 terabits per second.

• DDos protection: AWS Shield provides managed DDoS protection for applications running on AWS and is enabled for customers at no cost. AWS Shield Advanced offers enhanced detection, continuous access to the AWS DDoS Response Team (DRT), cost protection during attacks, and advanced diagnostics for enterprise applications.
• Layer 7 protection: AWS WAF protects against Layer 7 attacks through managed rule groups from AWS and AWS Marketplace sellers that cover OWASP Top 10 vulnerabilities including SQL injection, XSS, and remote file inclusion. Rate-based rules automatically block IPs that exceed request thresholds, protecting against application-layer DDoS and brute force attacks. Geo-blocking capabilities restrict access based on geographic location, while Bot Control uses machine learning to identify and block malicious bots while allowing legitimate traffic.
• AI for security: Amazon GuardDuty uses generative AI to enhance native security services, implementing AI capabilities to improve threat detection, investigation, and response through automated analysis.
• AI-powered enhancement: Organizations can build autonomous AI security agents using Amazon Bedrock to analyze AWS WAF logs, reason through attack data, and automate incident response. These agents detect novel attack patterns that signature-based systems miss, generate natural language summaries of security incidents, automatically recommend AWS WAF rule updates based on emerging threats, correlate attack indicators across distributed services to identify coordinated campaigns, and trigger appropriate remediation actions based on threat context. This helps enable more proactive threat detection and response capabilities, reducing mean time to detection and response.

Layer 2: Verifying identity

After requests pass edge protection, you must verify user identity and determine resource access. Traditional username/password authentication is vulnerable to credential stuffing, phishing, and brute force attacks, requiring robust identity management that supports multiple authentication methods and adaptive security responding to risk signals in real time.

Amazon Cognito provides comprehensive identity and access management for web and mobile applications through two components:

• User pools offer a fully managed user directory handling registration, sign-in, multi-factor authentication (MFA), password policies, social identity provider integration, SAML and OpenID Connect federation for enterprise identity providers, and advanced security features including adaptive authentication and compromised credential detection.
• Identity pools grant temporary, limited-privilege AWS credentials to users for secure direct access to AWS services without exposing long-term credentials.

Amazon Cognito adaptive authentication uses machine learning to detect suspicious sign-in attempts by analyzing device fingerprinting, IP address reputation, geographic location anomalies, and sign-in velocity patterns, then allows sign-in, requires additional MFA verification, or blocks attempts based on risk assessment. Compromised credential detection automatically checks credentials against databases of compromised passwords and blocks sign-ins using known compromised credentials. MFA supports both SMS-based and time-based one-time password (TOTP) methods, significantly reducing account takeover risk.

For advanced behavioral analysis, organizations can use Amazon Bedrock to analyze patterns across extended timeframes, detecting account takeover attempts through geographic anomalies, device fingerprint changes, access pattern deviations, and time-of-day anomalies.

Layer 3: The application front door

An API gateway serves as your application’s entry point. It must handle request routing, throttling, API key management, encryption and it needs to integrate seamlessly with your authentication layer and provide detailed logging for security auditing while maintaining high performance and low latency.

• Amazon API Gateway is a fully managed service for creating, publishing, and securing APIs at scale, providing critical security capabilities including SSL/TLS encryption with AWS Certificate Manager (ACM) to automatically handle certificate provisioning, renewal, and deployment. Request throttling and quota management protects backend services through configurable burst and rate limits with usage quotas per API key or client to prevent abuse, while API key management controls access from partner systems and third-party integrations. Request/response validation uses JSON Schema to validate data before reaching AWS Lambda functions, preventing malformed requests from consuming compute resources while seamless integration with Amazon Cognito validates JSON Web Tokens (JWTs) and enforces authentication requirements before requests reach application logic.
• GuardDuty provides AI-powered intelligent threat detection by analyzing API invocation patterns and identifying suspicious activity including credential exfiltration using machine learning. For advanced analysis, Amazon Bedrock analyzes API Gateway metrics and Amazon CloudWatch logs to identify unusual HTTP 4XX error spikes (for example, 403 Forbidden) that might indicate scanning or probing attempts, geographic distribution anomalies, endpoint access pattern deviations, time-series anomalies in request volume, or suspicious user agent patterns.

Layer 4: Network isolation

Application logic and data must be isolated from direct internet access. Network segmentation is designed to limit lateral movement if a security incident occurs, helping to prevent compromised components from easily accessing sensitive resources.

• Amazon Virtual Private Cloud (Amazon VPC) provides isolated network environments implementing a multi-tier architecture with public subnets for NAT gateways and application load balancers with internet gateway routes, private subnets for Lambda functions and application components accessing the internet through NAT Gateways for outbound connections, and data subnets with the most restrictive access controls. Lambda functions run in private subnets to prevent direct internet access, VPC flow logs capture network traffic for security analysis, security groups provide stateful firewalls following least privilege principles, Network ACLs add stateless subnet-level firewalls with explicit deny rules, and VPC endpoints enable private connectivity to Amazon DynamoDB, AWS Secrets Manager, and Amazon S3 without traffic leaving the AWS network.
• GuardDuty provides AI-powered network threat detection by continuously monitoring VPC Flow Logs, CloudTrail logs, and DNS logs using machine learning to identify unusual network patterns, unauthorized access attempts, compromised instances, and reconnaissance activity, now including generative AI capabilities for automated analysis and natural language security queries.

Layer 5: Compute security

Lambda functions executing your application code and often requiring access to sensitive resources and credentials must be protected against code injection, unauthorized invocations, and privilege escalation. Additionally, functions must be monitored for unusual behavior that might indicate compromise.

Lambda provides built-in security features including:

• AWS Identity and Access Management (IAM) execution roles that define precise resource and action access following least privilege principles
• Resource-based policies that control which services and accounts can invoke functions to prevent unauthorized invocations
• Environment variable encryption using AWS Key Management Services (AWS KMS) for variables at rest while sensitive data should use Secrets Manager function isolation designed so that each execution runs in isolated environments preventing cross-invocation data access
• VPC integration enabling functions to benefit from network isolation and security group controls
• Runtime security with automatically patched and updated managed runtimes
• Code signing with AWS Signer digitally signing deployment packages for code integrity and cryptographic verification against unauthorized modifications

TheAmazon Q Detector Library describes the detectors used during code reviews to identify security and quality issues in code. Detectors contain rules that are used to identify critical security vulnerabilities like OWASP Top 10 and CWE Top 25 issues, including secrets exposure and package dependency vulnerabilities. They also detect code quality concerns such as IaC best practices and inefficient AWS API usage patterns, helping developers maintain secure and high-quality applications.

Vulnerability management: Amazon Inspector provides automated vulnerability management, continuously scanning Lambda functions for software vulnerabilities and network exposure, using machine learning to prioritize findings and provide detailed remediation guidance.

Layer 6: Protecting credentials

Applications require access to sensitive credentials including database passwords, API keys, and encryption keys. Hardcoding secrets in code or storing them in environment variables creates security vulnerabilities, requiring secure storage, regular rotation, authorized-only access, and comprehensive auditing for compliance.

• Secrets Manager protects access to applications, services, and IT resources without managing hardware security modules (HSMs). It provides centralized secret storage for database credentials, API keys, and OAuth tokens in an encrypted repository using AWS KMS encryption at rest.
• Automatic secret rotation configures rotation for database credentials, automatically updating both the secret store and target database without application downtime.
• Fine-grained access control uses IAM policies to control which users and services access specific secrets, implementing least-privilege access.
• Audit trails log secret access in AWS CloudTrail for compliance and security investigations. VPC endpoint support is designed so that secret retrieval traffic doesn’t leave the AWS network.
• Lambda integration enables functions to retrieve secrets programmatically at runtime, designed so that secrets aren’t stored in code or configuration files and can be rotated without redeployment.
• GuardDuty provides AI-powered monitoring, detecting anomalous behavior patterns that could indicate credential compromise or unauthorized access.

Layer 7: Data protection

The data layer stores sensitive business information and customer data requiring protection both at rest and in transit. Data must be encrypted, access tightly controlled, and operations audited, while maintaining resilience against availability attacks and high performance.

Amazon DynamoDB is a fully managed NoSQL database providing built-in security features including:

• Encryption at rest (using AWS-owned, AWS managed, or customer managed KMS keys)
• Encryption in transit (TLS 1.2 or higher)
• Fine-grained access control through IAM policies with item-level and attribute-level permissions
• VPC endpoints for private connectivity
• Point-in-Time Recovery for continuous backups
• Streams for audit trails
• Backup and disaster recovery capabilities
• Global Tables for multi-AWS Region, multi-active replication designed to provide high availability and low-latency global access

GuarDuty and Amazon Bedrock provide AI-powered data protection:

• GuardDuty monitors DynamoDB API activity through CloudTrail logs using machine learning to detect anomalous data access patterns including unusual query volumes, access from unexpected geographic locations, and data exfiltration attempts.
• Amazon Bedrock analyzes DynamoDB Streams and CloudTrail logs to identify suspicious access patterns, correlate anomalies across multiple tables and time periods, generate natural language summaries of data access incidents for security teams, and recommend access control policy adjustments based on actual usage patterns versus configured permissions. This helps transform data protection from reactive monitoring to proactive threat hunting that can detect compromised credentials and insider threats.

Continuous monitoring

Even with comprehensive security controls at every layer, continuous monitoring is essential to detect threats that bypass defenses. Security requires ongoing real-time visibility, intelligent threat detection, and rapid response capabilities rather than one-time implementation.

• GuardDuty protects your AWS accounts, workloads, and data with intelligent threat detection.
• CloudWatch provides comprehensive monitoring and observability, collecting metrics, monitoring log files, setting alarms, and automatically reacting to AWS resource changes.
• CloudTrail provides governance, compliance, and operational auditing by logging all API calls in your AWS account, creating comprehensive audit trails for security analysis and compliance reporting.
• AI-powered enhancement with Amazon Bedrock provides automated threat analysis; generating natural language summaries of GuardDuty findings and CloudWatch logs, pattern recognition identifying coordinated attacks across multiple security signals, incident response recommendations based on your architecture and compliance requirements, security posture assessment with improvement recommendations, and automated response through Lambda and Amazon EventBridge that isolates compromised resources, revokes suspicious credentials, or notifies security teams through Amazon SNS when threats are detected.

Conclusion

Securing serverless microservices presents significant challenges, but as demonstrated, using AWS services alongside AI-powered capabilities creates a resilient defense-in-depth architecture that protects against current and emerging threats while proving that security and agility are not mutually exclusive.

Security is an ongoing process—continuously monitor your environment, regularly review security controls, stay informed about emerging threats and best practices, and treat security as a fundamental architectural principle rather than an afterthought.

Further reading

• Best practices for achieving success with Zero Trust
• AI/ML for security – AWS Prescriptive Guidance
• Automate cloud security vulnerability assessment and alerting using Amazon Bedrock
• Infrastructure protection – Serverless Applications Lens

If you have feedback about this blog post, submit them in the Comments section below. If you have questions about using this solution, start a thread in the EventBridge, GuardDuty, or Security Hub forums, or contact AWS Support.

December 2, 2019: Original publication date of this post.

At AWS, we encourage you to use automation. Not just to deploy your workloads and configure services, but to also help you quickly detect and respond to security events within your AWS environments. In addition to increasing the speed of detection and response, automation also helps you scale your security operations as your workloads in AWS increase and scale as well. For these reasons, security automation is a key principle outlined in the Well-Architected Framework, the AWS Cloud Adoption Framework, and the AWS Security Incident Response Guide.

Security response automation is a broad topic that spans many areas. The goal of this blog post is to introduce you to core concepts and help you get started. You will learn how to implement automated security response mechanisms within your AWS environments. This post will include common patterns that customers often use, implementation considerations, and an example solution. Additionally, we will share resources AWS has produced in the form of the Automated Security Response GitHub repo. The GitHub repo includes scripts that are ready-to-deploy for common scenarios.

What is security response automation?

Security response automation is a planned and programmed action taken to achieve a desired state for an application or resource based on a condition or event. When you implement security response automation, you should adopt an approach that draws from existing security frameworks. Frameworks are published materials which consist of standards, guidelines, and best practices in order help organizations manage cybersecurity-related risk. Using frameworks helps you achieve consistency and scalability and enables you to focus more on the strategic aspects of your security program. You should work with compliance professionals within your organization to understand any specific compliance or security frameworks that are also relevant for your AWS environment.

Our example solution is based on the NIST Cybersecurity Framework (CSF), which is designed to help organizations assess and improve their ability to help prevent, detect, and respond to security events. According to the CSF, “cybersecurity incident response” supports your ability to contain the impact of potential cybersecurity events.

Although automation is not a CSF requirement, automating responses to events enables you to create repeatable, predictable approaches to monitoring and responding to threats. When we build automation around events that we know should not occur, it gives us an advantage over a malicious actor because the automation is able to respond within minutes or even seconds compared to an on-call support engineer.

The five main steps in the CSF are identify, protect, detect, respond and recover. We’ve expanded the detect and respond steps to include automation and investigation activities.

Figure 1: The five steps in the CSF

The following definitions for each step in the diagram above are based on the CSF but have been adapted for our example in this blog post. Although we will focus on the detect, automate and respond steps, it’s important to understand the entire process flow.

• Identify: Identify and understand the resources, applications, and data within your AWS environment.
• Protect: Develop and implement appropriate controls and safeguards to facilitate the delivery of services.
• Detect: Develop and implement appropriate activities to identify the occurrence of a cybersecurity event. This step includes the implementation of monitoring capabilities which will be discussed further in the next section.
• Automate: Develop and implement planned, programmed actions that will achieve a desired state for an application or resource based on a condition or event.
• Investigate: Perform a systematic examination of the security event to establish the root cause.
• Respond: Develop and implement appropriate activities to take automated or manual actions regarding a detected security event.
• Recover: Develop and implement appropriate activities to maintain plans for resilience and to restore capabilities or services that were impaired due to a security event

Security response automation on AWS

AWS CloudTrail and AWS Config continuously log details regarding users and other identity principals, the resources they interacted with, and configuration changes they might have made in your AWS account. We are able to combine these logs with Amazon EventBridge, which gives us a single service to trigger automations based on events. You can use this information to automatically detect resource changes and to react to deviations from your desired state.

Figure 2: Automated remediation flow

As shown in the diagram above, an automated remediation flow on AWS has three stages:

1. Monitor: Your automated monitoring tools collect information about resources and applications running in your AWS environment. For example, they might collect AWS CloudTrail information about activities performed in your AWS account, usage metrics from your Amazon EC2 instances, or flow log information about the traffic going to and from network interfaces in your Amazon Virtual Private Cloud (VPC).
2. Detect: When a monitoring tool detects a predefined condition—such as a breached threshold, anomalous activity, or configuration deviation—it raises a flag within the system. A triggering condition might be an anomalous activity detected by Amazon GuardDuty, a resource out of compliance with an AWS Config rule, or a high rate of blocked requests on an Amazon VPC security group or AWS Web Application Firewall (AWS WAF) web access control list (web-acl).
3. Respond: When a condition is flagged, an automated response is triggered that performs an action you’ve predefined—something intended to remediate or mitigate the flagged condition.

Examples of automated response actions may include modifying a VPC security group, patching an Amazon EC2 instance, rotating various different types of credentials, or adding an additional entry into an IP set in AWS WAF that is part of a web-acl rule to block suspicious clients who triggered a threshold from a monitoring metric.

You can use the event-driven flow described above to achieve a variety of automated response patterns with varying degrees of complexity. Your response pattern could be as simple as invoking a single AWS Lambda function, or it could be a complex series of AWS Step Function tasks with advanced logic. In this blog post, we’ll use two simple Lambda functions in our example solution.

How to define your response automation

Now that we’ve introduced the concept of security response automation, start thinking about security requirements within your environment that you’d like to enforce through automation. These design requirements might come from general best practices you’d like to follow, or they might be specific controls from compliance frameworks relevant for your business.

Customers start with the run-books they already use as part of their Incident Response Lifecycle. Simple run-books, like responding to an exfiltrated credential, can be quickly mapped to automation especially if your run book calls for the disabling of the credential and the notification of on-call personnel. But it can be resource driven as well. Events such as a new AWS VPC being created might trigger your automation to immediately deploy your company’s standard configuration for VPC flowlog collection.

Your objectives should be quantitative, not qualitative. Here are some examples of quantitative objectives:

• Remote administrative network access to servers should be limited.
• Server storage volumes should be encrypted.
• AWS console logins should be protected by multi-factor authentication.

As an optional step, you can expand these objectives into user stories that define the conditions and remediation actions when there is an event. User stories are informal descriptions that briefly document a feature within a software system. User stories may be global and span across multiple applications or they may be specific to a single application.

For example:

“Remote administrative network access to servers should have limited access from internal trusted networks only. Remote access ports include SSH TCP port 22 and RDP TCP port 3389. If remote access ports are detected within the environment and they are accessible to outside resources, they should be automatically closed and the owner will be notified.”

Once you’ve completed your user story, you can determine how to use automated remediation to help achieve these objectives in your AWS environment. User stories should be stored in a location that provides versioning support and can reference the associated automation code.

You should carefully consider the effect of your remediation mechanisms in order to help prevent unintended impact on your resources and applications. Remediation actions such as instance termination, credential revocation, and security group modification can adversely affect application availability. Depending on the level of risk that’s acceptable to your organization, your automated mechanism can only provide a notification which would then be manually investigated prior to remediation. Once you’ve identified an automated remediation mechanism, you can build out the required components and test them in a non-production environment.

Sample response automation walkthrough

In the following section, we’ll walk you through an automated remediation for a simulated event that indicates potential unauthorized activity—the unintended disabling of CloudTrail logging. Outside parties might want to disable logging to avoid detection and the recording of their unauthorized activity. Our response is to re-enable the CloudTrail logging and immediately notify the security contact. Here’s the user story for this scenario:

“CloudTrail logging should be enabled for all AWS accounts and regions. If CloudTrail logging is disabled, it will automatically be enabled and the security operations team will be notified.”

A note about the sample response automation below as it references Amazon EventBridge: EventBridge was formerly referred to as Amazon CloudWatch Events. If you see other documentation referring to Amazon CloudWatch, you can find that configuration now via the Amazon EventBridge console page.

Additionally, we will be looking at this scenario through the lens of an account that has a stand-alone CloudTrail configuration. While this is an acceptable configuration, AWS recommends using AWS Organizations, which allows you to configure an organizational CloudTrail. These organizational trails are immutable to the child accounts so that logging data cannot be removed or tampered with.

In order to use our sample remediation, you will need to enable Amazon GuardDuty and AWS Security Hub in the AWS Region you have selected. Both of these services include a 30-day trial at no additional cost. See the AWS Security Hub pricing page and the Amazon GuardDuty pricing page for additional details.

Important: You’ll use AWS CloudTrail to test the sample remediation. Running more than one CloudTrail trail in your AWS account will result in charges based on the number of events processed while the trail is running. Charges for additional copies of management events recorded in a Region are applied based on the published pricing plan. To minimize the charges, follow the clean-up steps that we provide later in this post to remove the sample automation and delete the trail.

Deploy the sample response automation

In this section, we’ll show you how to deploy and test the CloudTrail logging remediation sample. Amazon GuardDuty generates the finding

Stealth:IAMUser/CloudTrailLoggingDisabled when CloudTrail logging is disabled, and AWS Security Hub collects findings from GuardDuty using the standardized finding format mentioned earlier. We recommend that you deploy this sample into a non- production AWS account.

Select the Launch Stack button below to deploy a CloudFormation template with an automation sample in the us-east-1 Region. You can also download the template and implement it in another Region. The template consists of an Amazon EventBridge rule, an AWS Lambda function, and the IAM permissions necessary for both components to execute. It takes several minutes for the CloudFormation stack build to complete.

1. In the CloudFormation console, choose the Select Template form, and then select Next.
2. On the Specify Details page, provide the email address for a security contact. For the purpose of this walkthrough, it should be an email address that you have access to. Then select Next.
3. On the Options page, accept the defaults, then select Next.
4. On the Review page, confirm the details, then select Create.
5. While the stack is being created, check the inbox of the email address that you provided in step 2. Look for an email message with the subject AWS Notification – Subscription Confirmation. Select the link in the body of the email to confirm your subscription to the Amazon Simple Notification Service (Amazon SNS) topic. You should see a success message like the one shown in Figure 3:
   

   Figure 3: SNS subscription confirmation

6. Return to the CloudFormation console. After the Status field for the CloudFormation stack changes to CREATE COMPLETE (as shown in Figure 4), the solution is implemented and is ready for testing.
   

   Figure 4: CREATE_COMPLETE status

Test the sample automation

You’re now ready to test the automated response by creating a test trail in CloudTrail, then trying to stop it.

1. From the AWS Management Console, choose Services > CloudTrail.
2. Select Trails, then select Create Trail.
3. On the Create Trail form:
   1. Enter a value for Trail name and for AWS KMS alias, as shown in Figure 5.
   2. For Storage location, create a new S3 bucket or choose an existing one. For our testing, we create a new S3 bucket.
      

      Figure 5: Create a CloudTrail trail

   3. On the next page, under Management events, select Write-only (to minimize event volume).
      

      Figure 6: Create a CloudTrail trail

4. On the Trails page of the CloudTrail console, verify that the new trail has started. You should see the status as logging, as shown in Figure 7.
   

   Figure 7: Verify new trail has started

5. You’re now ready to act like an unauthorized user trying to cover their tracks. Stop the logging for the trail that you just created:
   1. Select the new trail name to display its configuration page.
   2. In the top-right corner, choose the Stop logging button.
   3. When prompted with a warning dialog box, select Stop logging.
   4. Verify that the logging has stopped by confirming that the Start logging button now appears in the top right, as shown in Figure 8.
      

      Figure 8: Verify logging switch is off

   You have now simulated a security event by disabling logging for one of the trails in the CloudTrail service. Within the next few seconds, the near real-time automated response will detect the stopped trail, restart it, and send an email notification. You can refresh the Trails page of the CloudTrail console to verify through the Stop logging button at the top right corner.

   Within the next several minutes, the investigatory automated response will also begin. GuardDuty will detect the action that stopped the trail and enrich the data about the source of unexpected behavior. Security Hub will then ingest that information and optionally correlate with other security events.

   Following the steps below, you can monitor findings within Security Hub for the finding type TTPs/Defense Evasion/Stealth:IAMUser-CloudTrailLoggingDisabled to be generated:

6. In the AWS Management Console, choose Services > Security Hub.
   1. In the left pane, select Findings.
   2. Select the Add filters field, then select Type.
   3. Select EQUALS, paste TTPs/Defense Evasion/Stealth:IAMUser-CloudTrailLoggingDisabled into the field, then select Apply.
   4. Refresh your browser periodically until the finding is generated.
   

   Figure 9: Monitor Security Hub for your finding

7. Select the title of the finding to review details. When you’re ready, you can choose to archive the finding by selecting the Archive link. Alternately, you can select a custom action to continue with the response. Custom actions are one of the ways that you can integrate Security Hub with custom partner solutions.

Now that you’ve completed your review of the finding, let’s dig into the components of automation.

How the sample automation works

This example incorporates two automated responses: a near real-time workflow and an investigatory workflow. The near real-time workflow provides a rapid response to an individual event, in this case the stopping of a trail. The goal is to restore the trail to a functioning state and alert security responders as quickly as possible. The investigatory workflow still includes a response to provide defense in depth and uses services that support a more in-depth investigation of the incident.

Figure 10: Sample automation workflow

In the near real-time workflow, Amazon EventBridge monitors for the undesired activity.

When a trail is stopped, AWS CloudTrail publishes an event on the EventBridge bus. An EventBridge rule detects the trail-stopping event and invokes a Lambda function to respond to the event by restarting the trail and notifying the security contact via an Amazon Simple Notification Service (SNS) topic.

In the investigative workflow, CloudTrail logs are monitored for undesired activities. For example, if a trail is stopped, there will be a corresponding log record. GuardDuty detects this activity and retrieves additional data points regarding the source IP that executed the API call. Two common examples of those additional data points in GuardDuty findings include whether the API call came from an IP address on a threat list, or whether it came from a network not commonly used in your AWS account. An AWS Lambda function responds by restarting the trail and notifying the security contact. The finding is imported into AWS Security Hub, where it’s aggregated with other findings for analyst viewing. Using EventBridge, you can configure Security Hub to export the finding to partner security orchestration tools, SIEM (security information and event management) systems, and ticketing systems for investigation.

AWS Security Hub imports findings from AWS security services such as GuardDuty, Amazon Macie and Amazon Inspector, plus from third-party product integrations you’ve enabled. Findings are provided to Security Hub in AWS Security Finding Format (ASFF), which minimizes the need for data conversion. Security Hub correlates these findings to help you identify related security events and determine a root cause. Security Hub also publishes its findings to Amazon EventBridge to enable further processing by other AWS services such as AWS Lambda. You can also create custom actions using Security Hub. Custom actions are useful for security analysts working with the Security Hub console who want to send a specific finding, or a small set of findings, to a response or a remediation workflow.

Deeper look into how the “Respond” phase works

Amazon EventBridge and AWS Lambda work together to respond to a security finding.

Amazon EventBridge is a service that provides real-time access to changes in data in AWS services, your own applications, and Software-as-a-Service (SaaS) applications without writing code. In this example, EventBridge identifies a Security Hub finding that requires action and invokes a Lambda function that performs remediation. As shown in Figure 11, the Lambda function both notifies the security operator via SNS and restarts the stopped CloudTrail.

Figure 11: Sample “respond” workflow

To set this response up, we looked for an event to indicate that a trail had stopped or was disabled. We knew that the GuardDuty finding Stealth:IAMUser/CloudTrailLoggingDisabled is raised when CloudTrail logging is disabled. Therefore, we configured the default event bus to look for this event.

You can learn more regarding the available GuardDuty findings in the user guide.

How the code works

When Security Hub publishes a finding to EventBridge, it includes full details of the finding as discovered by GuardDuty. The finding is published in JSON format. If you review the details of the sample finding, note that it has several fields helping you identify the specific events that you’re looking for. Here are some of the relevant details:

{
   …
   "source":"aws.securityhub",
   …
   "detail":{
      "findings": [{
		…
    	“Types”: [
			"TTPs/Defense Evasion/Stealth:IAMUser-CloudTrailLoggingDisabled"
			],
		…
      }]
}

You can build an event pattern using these fields, which an EventBridge filtering rule can then use to identify events and to invoke the remediation Lambda function. Below is a snippet from the CloudFormation template we provided earlier that defines that event pattern for the EventBridge filtering rule:

# pattern matches the nested JSON format of a specific Security Hub finding
      EventPattern:
        source:
        - aws.securityhub
        detail-type:
          - "Security Hub Findings - Imported"
        detail:
          findings:
            Types:
              - "TTPs/Defense Evasion/Stealth:IAMUser-CloudTrailLoggingDisabled"

Once the rule is in place, EventBridge continuously monitors the event bus for events with this pattern.

When EventBridge finds a match, it invokes the remediating Lambda function and passes the full details of the event to the function. The Lambda function then parses the JSON fields in the event so that it can act as shown in this Python code snippet:

# extract trail ARN by parsing the incoming Security Hub finding (in JSON format)
trailARN = event['detail']['findings'][0]['ProductFields']['action/awsApiCallAction/affectedResources/AWS::CloudTrail::Trail']   

# description contains useful details to be sent to security operations
description = event['detail']['findings'][0]['Description']

The code also issues a notification to security operators so they can review the findings and insights in Security Hub and other services to better understand the incident and to decide whether further manual actions are warranted. Here’s the code snippet that uses SNS to send out a note to security operators:

#Sending the notification that the AWS CloudTrail has been disabled.
snspublish = snsclient.publish(
	TargetArn = snsARN,
	Message="Automatically restarting CloudTrail logging.  Event description: \"%s\" " %description
	)

While notifications to human operators are important, the Lambda function will not wait to take action. It immediately remediates the condition by restarting the stopped trail in CloudTrail. Here’s a code snippet that restarts the trail to reenable logging:

try:
	client = boto3.client('cloudtrail')
	enablelogging = client.start_logging(Name=trailARN)
	logger.debug("Response on enable CloudTrail logging- %s" %enablelogging)
except ClientError as e:
	logger.error("An error occured: %s" %e)

After the trail has been restarted, API activity is once again logged and can be audited.

This can help provide relevant data for the remaining steps in the incident response process. The data is especially important for the post-incident phase, when your team analyzes lessons learned to help prevent future incidents. You can also use this phase to identify additional steps to automate in your incident response.

How to Enable Custom Action and build your own Automated Response

Unlike how you set up the notification earlier, you may not want fully automate responses to findings. To set up automation that you can manually trigger it for specific findings, you can use custom actions. A custom action is a Security Hub mechanism for sending selected findings to EventBridge that can be matched by an EventBridge rule. The rule defines a specific action to take when a finding is received that is associated with the custom action ID. Custom actions can be used, for example, to send a specific finding, or a small set of findings, to a response or remediation workflow. You can create up to 50 custom actions.

In this section, we will walk you through how to create a custom action in Security Hub which will trigger an EventBridge rule to execute a Lambda function for the same security finding related to CloudTrail Disabled.

Create a Custom Action in Security Hub

1. Open Security Hub. In the left navigation pane, under Management, open the Custom actions page.
2. Choose Create custom action.
3. Enter an Action Name, Action Description, and Action ID that are representative of an action that you are implementing—for example Enable CloudTrail Logging.
4. Choose Create custom action.
5. Copy the custom action ARN that was generated. You will need it in the next steps.

Create Amazon EventBridge Rule to capture the Custom Action

In this section, you will define an EventBridge rule that will match events (findings) coming from Security Hub which were forwarded by the custom action you defined above.

1. Navigate to the Amazon EventBridge console.
2. On the right side, choose Create rule.
3. On the Define rule detail page, give your rule a name and description that represents the rule’s purpose (for example, the same name and description that you used for the custom action). Then choose Next.
4. Security Hub findings are sent as events to the AWS default event bus. In the Define pattern section, you can identify filters to take a specific action when matched events appear. For the Build event pattern step, leave the Event source set to AWS events or EventBridge partner events.
5. Scroll down to Event pattern. Under Event source, leave it set to AWS Services, and under AWS Service, select Security Hub.
6. For the Event Type, choose Security Hub Findings – Custom Action.
7. Then select Specific custom action ARN(s) and enter the ARN for the custom action that you created earlier.
8. Notice that as you selected these options, the event pattern on the right was updating. Choose Next.
9. On the Select target(s) step, from the Select a target dropdown, select Lambda function. Then, from the Function dropdown, select SecurityAutoremediation-CloudTrailStartLoggingLamb-xxxx. This lambda function was created as part of the Cloudformation template.
10. Choose Next.
11. For the Configure tags step, choose Next.
12. For the Review and create step, choose Create rule.

Trigger the automation

As GuardDuty and Security Hub have been enabled, after AWS Cloudtrail logging is enabled, you should see a security finding generated by Amazon GuardDuty and collected in AWS Security Hub.

1. Navigate to the Security Hub Findings page.
2. In the top corner, from the Actions dropdown menu, select the Enable CloudTrail Logging custom action.
3. Verify the CloudTrail configuration by accessing the AWS CloudTrail dashboard.
4. Confirm that the trail status displays as Logging, which indicates the successful execution of the remediation Lambda function triggered by the EventBridge rule through the custom action.

How AWS helps customers get started

Many customers look at the task of building automation remediation as daunting. Many operations teams might not have the skills or human scale to take on developing automation scripts. Because many Incident Response scenarios can be mapped to findings in AWS security services, we can begin building tools that respond and are quickly adaptable to your environment.

Automated Security Response (ASR) on AWS is a solution that enables AWS Security Hub customers to remediate findings with a single click using sets of predefined response and remediation actions called Playbooks. The remediations are implemented as AWS Systems Manager automation documents. The solution includes remediations for issues such as unused access keys, open security groups, weak account password policies, VPC flow logging configurations, and public S3 buckets. Remediations can also be configured to trigger automatically when findings appear in AWS Security Hub.

The solution includes the playbook remediations for some of the security controls defined as part of the following standards:

• AWS Foundational Security Best Practices (FSBP) v1.0.0
• Center for Internet Security (CIS) AWS Foundations Benchmark v1.2.0
• Center for Internet Security (CIS) AWS Foundations Benchmark v1.4.0
• Center for Internet Security (CIS) AWS Foundations Benchmark v3.0.0
• Payment Card Industry (PCI) Data Security Standard (DSS) v3.2.1
• National Institute of Standards and Technology (NIST) Special Publication 800-53 Revision 5

A Playbook called Security Control is included that allows operation with AWS Security Hub’s Consolidated Control Findings feature.

Figure 12: Architecture of the Automated Security Solution

Additionally, the library includes instructions in the Implementation Guide on how to create new automations in an existing Playbook.

You can use and deploy this library into your accounts at no additional cost, however there are costs associated with the services that it consumes.

Clean up

After you’ve completed the sample security response automation, we recommend that you remove the resources created in this walkthrough example from your account in order to minimize the charges associated with the trail in CloudTrail and data stored in S3.

Important: Deleting resources in your account can negatively impact the applications running in your AWS account. Verify that applications and AWS account security do not depend on the resources you’re about to delete.

Here are the clean-up steps:

• Delete the CloudFormation stack.
• Delete the trail you created in CloudTrail.
• If you created an S3 bucket for CloudTrail logs, you can also delete that S3 bucket.
• New accounts can try GuardDuty at no cost for 30 days. You can suspend or disable GuardDuty before the trial period ends to avoid charges.
• You can try AWS Security Hub at no cost with a 30-day free trial. You can avoid charges by disabling the service before the trial period is over.

Summary

You’ve learned the basic concepts and considerations behind security response automation on AWS and how to use Amazon EventBridge, Amazon GuardDuty and AWS Security Hub to automatically re-enable AWS CloudTrail when it becomes disabled unexpectedly. Additionally you got a chance to learn about the AWS Automated Security Response library and how it can help you rapidly get started with automations through Security Hub. As a next step, you may want to start building your own custom response automations and dive deeper into the AWS Security Incident Response Guide, NIST Cybersecurity Framework (CSF) or the AWS Cloud Adoption Framework (CAF) Security Perspective. You can explore additional automatic remediation solutions on the AWS Solution Library. You can find the code used in this example on GitHub.

If you have feedback about this blog post, submit them in the Comments section below. If you have questions about using this solution, start a thread in the
EventBridge, GuardDuty or Security Hub forums, or contact AWS Support.

Amazon Web Services (AWS) recommends using AWS IAM Identity Center to provide your workforce access to AWS managed applications—such as Amazon Q Developer—and AWS accounts. Today, we announced IAM Identity Center support for IPv6. To learn more about the advantages of IPv6, visit the IPv6 product page.

When you enable IAM Identity center, it provides an access portal for workforce users to access their AWS applications and accounts either by signing in to the access portal using a URL or by using a bookmark for the application URL. In either case, the access portal handles user authentication before granting access to applications and accounts. Supporting both IPv4 and IPv6 connectivity to the access portal helps facilitate seamless access for clients, such as browsers and applications, regardless of their network configuration.

The launch of IPv6 support in IAM Identity Center introduces new dual-stack endpoints that support both IPv4 and IPv6, so that users can connect using IPv4, IPv6, or dual-stack clients. Current IPv4 endpoints continue to function with no action required. The dual stack capability offered by Identity Center extends to managed applications. When users access the application dual-stack endpoint, the application automatically routes to the Identity Center dual-stack endpoint for authentication. To use Identity Center from IPv6 clients, you must direct your workforce to use the new dual-stack endpoints, and update configurations on your external identity provider (IdP), if you use one.

In this post, we show you how to update your configuration to allow IPv6 clients to connect directly to IAM Identity Center endpoints without requiring network address translation services. We also show you how to monitor which endpoint users are connecting to. Before diving into the implementation details, let’s review the key phases of the transition process.

Transition overview

To use IAM Identity Center from an IPv6 network and client, you need to use the new dual-stack endpoints. Figure 1 shows what the transition from IPv4 to IPv6 over dual-stack endpoints looks like when using Identity Center. The figure shows:

• A before state where clients use the IPv4 endpoints.
• The transition phase, when your clients use a combination of IPv4 and dual-stack endpoints.
• After the transition is complete, your clients will connect to dual-stack endpoints using their IPv4 or IPv6, depending on their preferences.

Figure 1: Transition from IPv4-only to dual-stack endpoints

Prerequisites

You must have the following prerequisites in place to enable IPv6 access for your workforce users and administrators:

• An existing IAM Identity Center instance
• Updated firewalls or gateways to include the new dual-stack endpoints
• IPv6 capable clients and networks

Work with your network administrators to update the configuration of your firewalls and gateways and to verify that your clients, such as laptops or desktops, are ready to accept IPv6 connectivity. If you have already enabled IPv6 connectivity for other AWS services, you might be familiar with these changes. Next, implement the two steps that follow.

Step 1: Update your IdP configuration

You can skip this step If you don’t use an external IdP as your identity source.

In this step, you update the Assertion Consumer Service (ACS) URL from your IAM Identity Center instance into your IdP’s configuration for single sign-on and the SCIM configuration for user provisioning. Your IdP’s capability determines how you update the ACS URLs. If your IdP supports multiple ACS URLs, configure both IPv4 and dual-stack URLs to enable a flexible transition. With that configuration, some users can continue using IPv4-only endpoints while others use dual-stack endpoints for IPv6. If your IdP supports only one ACS URL, to use IPv6 you must update the new dual-stack ACS URL in your IdP and transition all users to using dual-stack endpoints. If you don’t use an external IdP, you can skip this step and go to the next step.

Update both the SAML single sign-on and the SCIM provisioning configurations:

1. Update the single sign-on settings in your IdP to use the new dual-stack URLs. First, locate the URLs in the AWS Management Console for IAM Identity Center.
   1. Choose Settings in the navigation pane and then select Identity source.
   2. Choose Actions and select Manage authentication.
   3. in Under Manage SAML 2.0 authentication, you will find the following URLs under Service provider metadata:
      • AWS access portal sign-in URL
      • IAM Identity Center Assertion Consumer Service (ACS) URL
      • IAM Identity Center issuer URL
2. If your IdP supports multiple ACS URLs, then add the dual-stack URL to your IdP configuration alongside existing IPv4 one. With this setting, you and your users can decide when to start using the dual-stack endpoints, without all users in your organization having to switch together.
   

   Figure 2: Dual-stack single sign-on URLs

3. If your IdP does not support multiple ACS URLs, replace the existing IPv4 URL with the new dual-stack URL, and switch your workforce to use only the dual-stack endpoints.
4. Update the provisioning endpoint in your IdP. Choose Settings in the navigation pane and under Identity source, choose Actions and select Manage provisioning. Under Automatic provisioning, copy the new SCIM endpoint that ends in api.aws. Update this new URL in your external IdP.
   

   Figure 3: Dual-stack SCIM endpoint URL

Step 2: Locate and share the new dual-stack endpoints

Your organization needs two kinds of URLs for IPv6 connectivity. The first is the new dual-stack access portal URL that your workforce users use to access their assigned AWS applications and accounts. The dual-stack access portal URL is available in the IAM Identity Center console, listed as the Dual-stack in the Settings summary (you might need to expand the Access portal URLs section, shown in Figure 4).

Figure 4: Locate dual-stack access portal endpoints

This dual-stack URL ends with app.aws as its top-level domain (TLD). Share this URL with your workforce and ask them to use this dual-stack URL to connect over IPv6. As an example, if your workforce uses the access portal to access AWS accounts, they will need to sign in through the new dual-stack access portal URL when using IPv6 connectivity. Alternately, if your workforce accesses the application URL, you need to enable the dual-stack application URL following application-specific instructions. For more information, see AWS services that support IPv6.

The URLs that administrators use to manage IAM Identity Center are the second kind of URL your organization needs. The new dual-stack service endpoints end in api.aws as their TLD and are listed in the Identity Center service endpoints. Administrators can use these service endpoints to manage users and groups in Identity Center, update their access to applications and resources, and perform other management operations. As an example, if your administrator uses identitystore.{region}.amazonaws.com to manage users and groups in Identity Center, they should now use the dual-stack version of the same service endpoint which is identitystore.{region}.api.aws, so they can connect to service endpoints using IPv6 clients and networks.

If your users or administrators use an AWS SDK to access AWS applications and accounts or manage services, follow Dual-stack and FIPS endpoints to enable connectivity to the dual-stack endpoints.

After completing these two steps, your workforce and administrators can connect to IAM Identity Center using IPv6. Remember, these endpoints also support IPv4, so clients not yet IPv6-capable can continue to connect using IPv4.

Monitoring dual-stack endpoint usage

You can optionally monitor AWS CloudTrail logs to track usage of dual-stack endpoints. The key difference between IPv4-only and dual-stack endpoint usage is the TLD and appears in the clientProvidedHostHeader field. The following example shows the difference between these CloudTrail events for the CreateTokenWithIAM API call.

"CloudTrailEvent": {
  "eventName": "CreateToken",
  "tlsDetails": {
     "tlsVersion": "TLSv1.3",
     "cipherSuite": "TLS_AES_128_GCM_SHA256",
     "clientProvidedHostHeader": "oidc.us-east-1.amazonaws.com"
  }
}

"CloudTrailEvent": {
  "eventName": "CreateToken",
  "tlsDetails": {
     "tlsVersion": "TLSv1.3",
     "cipherSuite": "TLS_AES_128_GCM_SHA256",
     "clientProvidedHostHeader": "oidc.us-east-1.api.aws"
  }
}

Conclusion

IAM Identity Center now allows clients to connect over IPv6 natively with no network address translation infrastructure. This post showed you how to transition your organization to use IPv6 with Identity Center and its integrated applications. Remember that existing IPv4 endpoints will continue to function, so you can transition at your own pace. Also, no immediate action is required by you. However, we recommend planning your transition to take advantage of IPv6 benefits and meet compliance requirements. If you have questions, comments, or concerns, contact AWS Support, or start a new thread in the IAM Identity Center re:Post channel.

 
If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, contact AWS Support.