How Purple Team Exercises Can Enhance Your Threat Management Strategy

Proactively addressing cyberthreats is a critical part of any organization’s threat and vulnerability management strategy. As the tactics and techniques of attackers evolve, it’s more important than ever for organizations to constantly adapt their security measures to meet more complex and sophisticated threats.

With all of the components that come with an effective security strategy, how can you be sure that your security posture is agile enough to respond to the latest emerging threats? One of the most effective ways to fine-tune your defenses is with adversary simulation, a tactic that involves simulating real-world attacks on your systems, processes and technologies.

When it comes to threat and vulnerability management strategies, it’s important to consider your organization’s security maturity level before jumping into a new exercise or technique.

Think of your overall threat and vulnerability management posture like a pyramid. This pyramid is made up of three levels:

1. Vulnerability assessment strategies lie at the bottom of the pyramid. Broad in scope, these assessments are typically conducted with the aid of automated scanning tools, offering insights into discovered vulnerabilities. These strategies should typically be implemented during the early stages of your organization’s threat and vulnerability management program, as the intention is generally to kick off tasks like patch management or vulnerability management projects.
   
   
2. Penetration testing is the middle of the pyramid. Penetration tests validate the identified vulnerabilities by simulating ways in which bad actors may exploit them. Pen tests are more focused activities, as experts will put your environment’s preventive controls to the test by “attacking” the environment in an attempt to gain access to systems, networks or permissions that should be inaccessible without the proper authorizations.
   
   
3. Adversary simulation is at the very top of the pyramid and comprises two parts: purple teaming and red teaming. These exercises are designed for organizations with higher security maturity levels. While red teaming exercises are a final test of an organization’s threat and vulnerability management program, purple teaming lies between traditional penetration testing and red teaming exercises. Both exercises allow organizations to simulate real-world attack scenarios and test their detection and response capabilities.

When it comes to adapting to emerging threats, adversary simulation exercises are critical to help ensure that your security measures evolve in alignment with the changing threat landscape. While they differ in scope and in practice, both red team and purple team exercises simulate adversarial tactics and put the people, processes and technology of organizations to the test. The essence of these exercises lies in the continuous feedback loop: red teams simulate adversarial tactics while blue teams adapt their detection and response strategies based on observed vulnerabilities and the simulated attacks.

Red teaming represents the ultimate test of your threat and vulnerability management program. During a red team exercise, the red team challenges assumptions and pushes the limits of your organization’s security posture while the blue team prepares to defend against any potential threats. The red team performs these adversarial exercises covertly in an attempt to achieve a key objective, like compromising your organization’s development pipeline or breaching the perimeter, for example.  Since the blue team may not know when or where the red team is going to attack, red team exercises are essentially a “trial by fire” of your security controls.

Purple team exercises, on the other hand, are designed to foster collaboration and shared learning by bridging the gap between offensive and defensive security strategies. Unlike traditional red team exercises, purple teaming requires both teams to be aware of these exercises and actively participate throughout.

During a purple team exercise, both red and blue teams work together to devise attack scenarios based on current threat intelligence, and current tactics, techniques and procedures (TTPs). Through hands-on scenarios and knowledge transfer, both teams develop a deeper understanding of potential risks and the behaviors of attackers in order to improve the organization’s detection capabilities. The outcome is not only enhanced technical capabilities but also improved communication and collaboration among security operations stakeholders. By working together, both teams can identify gaps in detection and response capabilities and develop more comprehensive strategies.

Effectively implementing purple team exercises requires a systematic and comprehensive approach that clearly defines the objectives for each exercise, ensuring alignment with your overall security goals.

Keep the following considerations in mind before jumping into a purple team exercise:

• Establish rules of engagement (ROE). The ROE lays the groundwork for participation, expectations and the scenarios to be explored. It will help determine how your organization is currently architected with policies and technology, always taking specific verticals into account. This preliminary step ensures that both red and blue teams operate with a shared understanding of the parameters guiding their interactions.
• Ensure TTPs are relevant to your industry and organization. To get the most out of a purple team exercise, it’s important to tailor specific TTPs to your organization’s unique threat landscape. Leveraging current threat intelligence and industry-specific risks enables these exercises to focus on scenarios that matter most to the business.
• Prioritize high-impact activities. Specificity is key to obtaining a worthwhile return on investment. For example, it may not be worth the time or effort for a small private business to use purple team exercises to prepare for a nation-state attack. Communicate with key stakeholders to identify your organization’s most critical assets — its "crown jewels" — to more effectively prioritize low-cost, high-impact activities.
• Review insights. The collaborative nature of purple teaming demands that both red and blue team members are in constant communication, sharing insights and learning from one another. One of the most important steps in purple teaming is establishing a post-exercise debriefing, where teams can reflect on observations, measure success and identify actionable improvements to their security posture.

What can cause purple team exercises to stall or even fail? While adversary simulation exercises offer numerous benefits for organizations ready to implement them, it’s important to be aware of possible pitfalls that can hinder the effectiveness of the exercise. A few of the most common include:

• Overestimating security maturity levels: Organizations shouldn’t enter into purple team exercises assuming that they have reached optimal levels of maturity. A security skills gap can cause hiccups in the exercise and even outright failure in the worst of cases. It’s crucial to tailor purple team exercises to your organization's capabilities and, if necessary, tone them down for less experienced teams.

• Underestimating time and resources: Conducting a successful purple team exercise requires significant time and resources from all parties involved. One session will likely take an entire workday and preparation for the exercise will likely take much longer. Be sure to plan accordingly to ensure sufficient bandwidth is dedicated to the exercise.

An expert partner with extensive threat and vulnerability management experience can help maximize your organization’s investment in purple or red team exercises. When engaging a security partner, be sure to consider one with years of experience conducting security assessments informed by the real-world perspectives of experienced security engineers and consultants.