How Zero Trust Will Change Incident Response

What Is Incident Response?

Incident response involves responding to potential threats, such as unauthorized access to a corporate network. An event can be a sign of a breach or a false positive. However, it still requires investigation to determine the appropriate response.

The goal of incident response is to detect and remediate attacks quickly. Organizations use incident response to minimize risks, respond promptly, and prevent breaches. An incident response plan is generally considered the first line of defense and, ideally, the last if it helps you prevent a breach or quickly block an attack.

Here are the three main components of incident response:

• Incident response plan—a clear and concise plan that outlines how the organization responds to each type of security threat, providing detailed instructions and definitions of roles and responsibilities. 

• Incident response team—security experts that work in-house or externally as third parties hired to protect the organization against various security threats.

• Incident response technology—supports the team in detecting, blocking, and analyzing threats. Some incident response solutions can also intelligently respond to threats.

NIST Incident Response Steps

The National Institute of Standards and Technology (NIST) drafted the Incident Handling Guide with guidelines for incident responders. Here are the four phases for incident handling outlined by NIST:

• Preparation—the incident response team must have a well established incident response plan indicating who is responsible for each part of incident response and how to deal with specific types of incidents. 

• Detection and analysis—the cyber incident response team detects cyber incidents and collects relevant data, analyzing that data. They document and prioritize the incident when necessary before informing the appropriate authorities. 

• Containment, eradication, and recovery—following an incident, the cyber incident response team must create and implement strategies to stop the attack, remove the threat and begin the recovery process. 

• Post-incident activity—once an organization successfully resolves an incident, the team should go back to the first step and prepare for the next incident. Knowledge gained from each incident should inform the next preparation process, helping add new information or fine-tune processes. 

The NIST incident response guide suggests that preparing for incidents is an organization’s best defense.

What is Zero Trust?

Zero trust is a new approach to cybersecurity that secures an organization by doing away with implicit trust and continuously authenticating each stage of digital interaction. 

The “never trust, always verify” model informs the zero trust approach. This process works according to the premise that any user, resource, or asset is untrustworthy. Zero trust encompasses a set of principles, initiatives, policies, architecture, and frameworks. 

Here are characteristics of zero trust networks (ZTN): 

• ZTN is an end-to-end functional solution that involves zero trust technology, policies, and systems designed to manage security. 

• ZTNs are architected to manage security related to identities, credentials, identities, operations, access, hosting environment, endpoints, and infrastructure.

• A zero trust network deployment can have components that are cloud-based or on-premise. 

With a zero trust model, an organization must continually evaluate and authenticate all users before providing them with access to sensitive organizational data. 

Zero Trust and Incident Response

Incident response is a critical organizational process used to detect cyber attacks and respond to them in a timely manner, preventing or minimizing damage to the organization. 

Zero trust networks provide new capabilities for incident responders. In the past, a security incident would require detailed investigation just to understand where the network was breached and how. In a zero trust environment, detailed information is available about suspicious access requests, and which individual user or device was involved in the incident.

The following principles can guide incident response in a zero trust environment:

• Assume breach—the corporate network and insiders are not trusted. Focus on deterring violations and limiting incident damage for attackers already inside the network perimeter.

• Monitor identities, devices, applications, and data—a zero-trust network provides detailed information about these four elements with regard to any user request. When incident responders discover an incident, they can relate to the specific entities, applications and data involved.

• React to any anomaly—in a traditional network, incident responders received thousands of alerts, most of which were false positives. However, in a zero-trust environment alerts are much more focused and indicate a violation of network access rules, so they are more likely to indicate a real incident.

• Automated response—in a zero-trust environment, it is critical to put in place automatic detection and mitigation. Systems like zero trust network access (ZTNA) can detect anomalous access requests and automatically change network segmentation rules to protect sensitive systems. Automated response should provide a first line of defense, and deeper investigation can be carried out by human security teams.

In a world of zero trust, security incidents will still happen. No technology can magically eliminate security threats. However, narrowing down the domain of trust will reduce the involvement of multiple resources in a single event. In other words, when an incident occurs, the smaller the trust area, the lesser the risk that other systems face. This enables faster detection, more efficient response, and greater confidence that a threat has really been eradicated.

Conclusion

In this article, I explained the basics of incident response and zero trust and explained how the zero trust revolution will impact how we defend computing systems:

• Assume breach mentality—an incident response process must take into account that attackers are already inside the secured perimeter.

• Visibility of devices and applications—in order to respond to security incidents, security teams must have complete visibility of the devices accessing corporate systems, and what applications, data or capabilities they are using.

• Continuous verification—the network must be able to continuously verify access attempts and any anomaly in verifications should be treated as a security incident.

• Automated response—in a zero trust environment, automated remediation is key to incident response, but it must be combined with human oversight and identification of root cause.

I hope this will be useful as you adapt your organization’s security processes to a new zero trust environment.