Applying Forensic Principles to Incident Response in the CISA Playbook

In today's digital landscape, the threat of cyber incidents looms large over organizations of all sizes and sectors. Whether it's a breach, a data leak, or an insider threat, the key to mitigating damage and restoring normalcy lies in a well-structured incident response plan. Fortunately, the CISA Incident Response Playbook provides a solid framework for cybersecurity teams at private and public sector organizations alike.

Recently, in a webinar led by Justin Tolman, Exterro Digital Forensics Evangelist and an expert in cybersecurity and forensics, he presented several critical insights into the forensic aspect of cybersecurity incident response. Let's explore how six of these principles can be applied effectively. If you’d rather listen to the webinar on demand, it’s also available on our website here.

Prioritizing Security First

In any incident, the foremost priority is to ensure stability and security of organizational infrastructure and data systems. At the initial stages of incident response, the priority is not rushing into attributing blame or identifying suspects, but rather focusing on securing the environment. This resonates deeply with the essence of digital forensic investigations, where the primary goal is to gather evidence while ensuring the integrity of the system.

Preparation: Infrastructure Monitoring and Process Documentation

Preparation is foundational to successfully integrating digital forensic capabilities into your incident response plan. Establishing a clear picture of the infrastructure and understanding what constitutes normal operations is crucial. If you don’t understand what normal looks like–for network traffic, application usage, data transfers, and other key metrics–how can you possibly identify abnormal or concerning trends?

Tolman also stresses the need for accurate documentation outlining response procedures. Have a process in place before an incident happens, and you have the advantage of knowing what your next step is. Without a response plan, the cyberattacker retains the upper hand for far longer. In the realm of forensics, this translates to deploying forensic agents across endpoints, establishing baselines, and ensuring readiness for potential breaches.

Investigation: Collecting and Analyzing Data

During investigation, collecting and preserving data becomes paramount. However, balancing the need for thorough analysis with time constraints is vital. Tolman suggests a tiered approach to data collection based on the severity of the breach. Once you’ve secured the larger environment, it’s time to collect data so you can understand what went wrong and learn from the incident.

Whether you're using a persistent agent that's always installed on the endpoint or an ad hoc agent, you can use those agents to either turn off the machine as we talked about earlier, so that we can forensically image it later, or you can close off all the ports except for the one your forensic software connects to. That way you can still perform forensic analysis, but the system doesn't have access to anything else, giving the ability to cause greater damage. 

Remediation: Swift Action and Confirmation

Swift remediation is key to containment and damage control. Leveraging forensic agents to isolate endpoints and remediate compromised systems accelerates response efforts. Confirming the effectiveness of remedial actions through forensic examination ensures that no lingering threats remain. A remote agent installed on all endpoints gives your incident response team the ability to delete and kill processes, delete files, or otherwise act on the source of the cybersecurity incident.

Communication: Learning and Sharing Insights

Effective communication is pivotal throughout the incident response lifecycle. Tolman advocates for comprehensive post-incident debriefs to identify areas for improvement. Sharing forensic findings and lessons learned facilitates organizational learning and strengthens future resilience against threats. Not to mention, it also can provide other organizations with information that allows them to protect themselves, or at least remediate similar incidents faster.

Continuous Improvement: Iterative Cycle of Response

The incident response cycle is not a one-time endeavor but an ongoing iterative process. Each cycle presents an opportunity for refinement and enhancement. By embracing a culture of continuous improvement, organizations can evolve their response capabilities and stay ahead of emerging threats.

Conclusion: Embracing Forensic Principles in Incident Response

As Tolman articulates, integrating forensic principles into incident response frameworks is essential for effective cybersecurity management. By prioritizing security, meticulous preparation, thorough investigation, swift remediation, and transparent communication, organizations can navigate through crises with resilience and confidence. The journey towards cyber resilience begins with a commitment to forensic excellence and a relentless pursuit of improvement.

In the ever-evolving landscape of cyber threats, these foundational principles can help point your organization towards more robust incident response. As organizations embrace these principles and cultivate a proactive stance towards security, they forge a formidable defense against the ever-present threat of cybercrime. 

Listen to the webinar on demand on our website here.