SEC04-BP03 Correlate and enrich security alerts - Security Pillar
Implementation guidanceResources

SEC04-BP03 Correlate and enrich security alerts

Unexpected activity can generate multiple security alerts by different sources, requiring further correlation and enrichment to understand the full context. Implement automated correlation and enrichment of security alerts to help achieve more accurate incident identification and response.

Desired outcome: As activity generates different alerts within your workloads and environments, automated mechanisms correlate data and enrich that data with additional information. This pre-processing presents a more detailed understanding of the event, which helps your investigators determine the criticality of the event and if it constitutes an incident that requires formal response. This process reduces the load on your monitoring and investigation teams.

Common anti-patterns:

  • Different groups of people investigate findings and alerts generated by different systems, unless otherwise mandated by separation of duty requirements.  

  • Your organization funnels all security finding and alert data to standard locations, but requires investigators to perform manual correlation and enrichment.

  • You rely solely on the intelligence of threat detection systems to report on findings and establish criticality.

Benefits of establishing this best practice: Automated correlation and enrichment of alerts helps to reduce the overall cognitive load and manual data preparation required of your investigators. This practice can reduce the time it takes to determine if the event represents an incident and initiate a formal response. Additional context also helps you accurately assess the true severity of an event, as it may be higher or lower than what any one alert suggests.

Level of risk exposed if this best practice is not established: Low 

Implementation guidance

Security alerts can come from many different sources within AWS, including:

In their most fundamental form, alerts contain information about who (the principal or identity) is doing what (the action taken) to what (the resources affected). For each of these sources, identify if there are ways you can create mappings across identifiers for these identities, actions, and resources as the foundation for performing correlation. This can take the form of integrating alert sources with a security information and event management (SIEM) tool to perform automated correlation for you, building your own data pipelines and processing, or a combination of both.

An example of a service that can perform correlation for you is Amazon Detective. Detective performs ongoing ingestion of alerts from various AWS and third-party sources and uses different forms of intelligence to assemble a visual graph of their relationships to aid investigations.

While the initial criticality of an alert is an aid for prioritization, the context in which the alert happened determines its true criticality. As an example, Amazon GuardDuty can alert that an Amazon EC2 instance within your workload is querying an unexpected domain name. GuardDuty might assign low criticality to this alert on its own. However, automated correlation with other activity around the time of the alert might uncover that several hundred EC2 instances were deployed by the same identity, which increases overall operating costs. In this event, GuardDuty might publish this correlated event context as a new security alert and adjust the criticality to high, which would expedite further action.

Implementation steps

  1. Identify sources for security alert information. Understand how alerts from these systems represent identity, action, and resources to determine where correlation is possible.

  2. Establish a mechanism for capturing alerts from different sources. Consider services such as Security Hub, EventBridge, and CloudWatch for this purpose.

  3. Identify sources for data correlation and enrichment. Example sources include CloudTrail, VPC Flow Logs, Amazon Security Lake, and infrastructure and application logs.

  4. Integrate your alerts with your data correlation and enrichment sources to create more detailed security event contexts and establish criticality.

    1. Amazon Detective, SIEM tooling, or other third-party solutions can perform a certain level of ingestion, correlation, and enrichment automatically.

    2. You can also use AWS services to build your own. For example, you can invoke an AWS Lambda function to run an Amazon Athena query against AWS CloudTrail or Amazon Security Lake, and publish the results to EventBridge.

Resources

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