Automating Incident Response
Overview
This lab is designed to simulate and respond to a real-world cloud security incident involving a compromised EC2 instance within the AWS environment. The focus is on building and executing automated incident response (IR) playbooks to detect and remediate malicious activity without manual intervention, leveraging AWS-native tools and services.
Scenario Summary
An adversary has successfully compromised an EC2 instance, potentially via a vulnerability such as an OS command injection. After gaining unauthorized access, the attacker:
- Installs a TOR client to communicate anonymously with an external command-and-control (C2) server.
- Attempts to perform Bitcoin mining and establish a connection to a known malicious IP address.
Incident Response lifecycle
Incident response (IR) is a structured process organizations follow to detect, investigate, and mitigate security incidents. The goal is to minimize damage, reduce recovery time and costs, and prevent future incidents.
This lifecycle is traditionally divided into four key phases:
Preparation: Establish and configure the tools, processes, and roles necessary for responding to incidents. In this lab, AWS services like CloudTrail, GuardDuty, and Lambda are configured to support automated detection and action.
Detection and Analysis: Identify suspicious activity through logs, alerts, or behavioral anomalies. For example, the use of GuardDuty helps detect signs of compromise such as TOR traffic or crypto-mining behavior.
Containment, Eradication, and Recovery: Once a threat is confirmed, isolate the affected resource (e.g., EC2 instance), stop malicious processes, collect forensic data, and recover the system to a known good state.
Post-Incident Activities: Review and document the incident response to improve future preparedness. This includes analyzing what happened, what was done, and how to enhance the automation or response process going forward.
Post-incident activities are not a one-time step but part of a continuous feedback loop. Insights gained from each incident help refine detection rules, strengthen security controls, and improve response playbooks. These lessons feed back into the preparation phase ensuring the organization is better equipped for future threats and able to respond more effectively over time.
Automated Incident Response Playbook Approaches
In this lab, we will implement three types of automated incident response (IR) playbooks using AWS-native services. Each approach provides distinct advantages and trade-offs depending on the complexity and duration of the remediation tasks.
1. Lambda-based IR Playbook
This approach uses a single AWS Lambda function to execute remediation actions as soon as an incident is detected. It is the simplest and fastest method to deploy. However, it comes with an important limitation:
- Execution time is capped at 15 minutes, which means it cannot accommodate long-running tasks, such as waiting for an EBS snapshot to complete or performing detailed forensic collection.
- Best suited for immediate and lightweight actions, such as tagging, isolating the instance via security group changes, or sending alerts.
2. Step Functions-based IR Playbook
This method uses AWS Step Functions to orchestrate the incident response as a modular state machine, enabling a more flexible and robust IR process.
- Unlike Lambda, there is no strict execution timeout, allowing for complex, multi-step workflows that may span several minutes or even hours.
- Tasks can be broken into independent, manageable states, including parallel execution, retries, wait conditions, and failure handling logic.
- Ideal for scenarios requiring sequenced actions, such as taking snapshots, gathering forensic data, notifying multiple systems, and then terminating or quarantining the instance.
By comparing both approaches, this lab highlights how AWS automation tools can be tailored to meet different response needs from rapid reaction to comprehensive remediation pipelines.
3. System Manager Automation based IR Playbook (coming soon)
Goals of the Workshop
By the end of this workshop, you will have learned how to:
- Perform automated basic incident response tasks follow the incident response life cycle.
- Understand the range of possible remediation actions and the effort involved in executing them.
This workshop length is around 3hrs, even if you dont complete it visit the clean up resources part to avoid the fees.