What is Purple Team?

In cybersecurity, purple team strategy combines the offensive tactics of the red team with the defensive measures of the blue team to create a unified cybersecurity approach. Enhanced communication and cooperation are fundamental to this strategy, which focuses on continuously identifying and mitigating security gaps. As a result, purple teaming ensures a cybersecurity framework that is both robust and responsive to evolving threats.

In this blog, we will delve into the inner workings of purple teaming, its integral role in bolstering cybersecurity defenses, and practical insights into how this approach can be strategically implemented to stay one step ahead of attackers.

What Is a Purple Team?

The purple team is a strategic mindset in cybersecurity that combines the skills of both red and blue team professionals to find and fix any potential attack paths that could allow adversaries to compromise an organization's IT infrastructure.

This combined strategy functions to strengthen an organization's security posture through a continuous cycle of feedback, knowledge transfer, and sophisticated cyberattack simulations. These simulations aim to detect potential attack paths that an adversary is likely to use to reach their objectives within an organization's IT infrastructure. Once these paths are identified, the Purple Team proposes actionable detection and mitigation strategies.

It's important to clarify that a purple team is generally not a standalone entity, but rather a mindset that leverages the strengths of both the red and blue teams. Their joint objective is the ongoing enhancement of cybersecurity. However, in larger organizations, it's quite common to establish a separate, dedicated purple team. Their responsibilities encompass simulating cyber attacks and performing penetration testing, all with the goal of uncovering and recommending solutions for security vulnerabilities.

What Is Purple Teaming?

Purple teaming is an exercise in organizational strategy that combines the efforts of both red and blue teams. The red team performs complex cyberattack simulations on an organization's security infrastructure, while the blue team evaluates the effectiveness of the security controls in response. It also develops and implements detection and mitigation strategies against the simulated threats.

 
Figure 1. Collaboration of Red and Blue Teams for Purple Teaming.

The aim of a purple teaming exercise is to maximize an organization's cyber defense capabilities by ensuring that these two groups work together, learning from each other's insights, tactics, and strategies.

However, it's essential to understand that a purple team is not an additional team. Rather, it represents an operational strategy aimed at enhancing security through improved communication, collaboration, and shared understanding between the red and blue teams. 

Thus, the purple teaming approach helps organizations continuously identify and address security vulnerabilities, creating a more robust and effective defense against real-world cyber threats.

What Is the Purpose of Purple Team in Cybersecurity?

The purpose of a purple team is to leverage the combined expertise of both offensive and defensive teams to strengthen an organization's security posture, enhance detection and response capabilities, and proactively identify and mitigate vulnerabilities and risks.

The primary goals of a purple team can be categorized under five main points.

• Enhancing Detection and Response Capabilities

• Evaluating Security Controls

• Identifying and Prioritizing Vulnerabilities

• Enhancing Communication and Collaboration

• Continuous Improvement

Each key point is provided with a brief explanation.

a. Enhancing Detection and Response Capabilities 

By conducting joint exercises and simulations, the purple team helps the blue team to improve their ability to detect and respond to real-world cyber threats. The red team provides realistic attack scenarios, allowing the blue team to identify and address any weaknesses or gaps in their detection and response processes.

b. Evaluating Security Controls

The purple team assesses the effectiveness of an organization’s existing security controls, such as Next-Generation Firewalls (NGFW), Intrusion Detection and Prevention Systems (IDS & IPS), and endpoint protection solutions like Endpoint Detection and Response (EDR), Extended Detection and Response (XDR), as well as Security Information and Event Management (SIEM). 

By working together, the red team, which simulates attacks, can attempt to bypass these controls while the blue team, focused on defense, monitors and analyzes their activities. This collaboration helps identify potential vulnerabilities and areas where security controls can be strengthened.

c. Identifying and Prioritizing Vulnerabilities

The purple team exercises provide valuable insights into an organization's vulnerabilities and potential attack paths that an adversary can traverse to accomplish their objectives. The red team identifies weaknesses and exploits them, while the blue team evaluates the impact and severity of the vulnerabilities and develops actionable remediation strategies. This collaborative approach helps prioritize remediation efforts based on the real-world risk posed to the organization.

d. Enhancing Communication and Collaboration

The purple team fosters better communication and collaboration between the red and blue teams. By working together, these teams can share knowledge, techniques, and best practices. This collaboration helps bridge the gap between offensive and defensive perspectives, leading to a more holistic understanding of the organization's security posture.

e. Continuous Improvement

The purple team approach promotes a cycle of continuous improvement. Through regular collaboration and joint exercises, the organization can refine their security controls, incident response procedures, and overall cybersecurity strategy. Lessons learned from the purple team exercises can be used to update policies, implement new technologies, and train personnel effectively.

Overall, the purpose of a purple team is to improve an organization's cybersecurity defenses by facilitating collaboration and knowledge sharing between the red team and blue team. 

What Is the Benefit of Conducting a Purple Teaming Exercise at Your Organization?

By conducting continuous purple team exercises, an organization can significantly bolster its security posture. This is achieved by uniting the expertise of both offensive and defensive teams, which in turn enhances threat response, facilitates the sharing of knowledge, and ensures the most effective use of security resources.

The benefits of conducting a purple teaming exercise in your organization can be categorized into six main points.

• Integrated Approach to Cyber Threat Management 

• Improved Incident Response

• Knowledge Transfer 

• Bridging the Gap Between Red and Blue Teams

• Increased Return of Investment (ROI)

• Adaptability to Evolving Threats 

Each main point is provided with a brief explanation.

a. Integrated Approach to Cyber Threat Management

Purple teaming is an integrated approach to threat management. By combining the offensive tactics of the red team and the defensive strategies of the blue team, purple teaming exercises can 

• identify possible attack paths that adversaries can take to compromise an organization’s systems and network, and 

• develop mitigation solutions collaboratively, 

resulting in a more robust cybersecurity strategy.

Figure 2. The Build, Attack, Defend Pyramid.

b. Improved Incident Response

With the collaboration of red and blue teams, purple teaming enables improved incident response. They can simulate attacks, evaluate the organization's response, and then fine-tune that response based on actual results. This not only leads to faster reaction times but also more effective mitigation strategies.

c. Knowledge Transfer

Purple teaming fosters a learning environment, where knowledge about attack and defense tactics is shared freely. This ongoing exchange leads to constant improvement, boosting the overall cybersecurity maturity of the organization.

d. Bridging the Gap Between Red and Blue Teams

Purple teaming acts as a bridge between the red and blue teams, facilitating communication and cooperation. This alignment eliminates any potential silos, ensuring that all teams are working towards the common goal of securing the organization.

e. Increased ROI

Through coordinated efforts, purple teaming helps organizations maximize the return on investment in cybersecurity tools and personnel. By identifying blind spots and reinforcing defenses, they ensure that resources are utilized effectively and efficiently.

f. Adaptability to Evolving Threats

Cyber threats are constantly evolving, and a static defense may not be sufficient. Purple teaming exercises provide an active defense mechanism, continually testing, learning, and adapting to new tactics, techniques, and procedures in the threat landscape.

What Is Red Team Blue Team and Purple Team? 

Red Team

A Red Team is a group of offensive security professionals that simulates attacks on an organization's systems and networks to identify vulnerabilities. They use techniques similar to those of real-world attackers, and their goal is to help organizations identify and fix security gaps before they are exploited.

Blue Team

A Blue Team is a defensive security team that works to protect an organization's systems and networks from attack. They monitor for threats, respond to incidents, and develop and implement security controls.

Purple Team

The purple team is a mindset that entails a collaboration between red and blue teams, bringing together the defensive and offensive expertise of both to forge a more effective security strategy. This combination allows organizations to identify and respond to threats with a speed and efficiency that surpasses what either red or blue teams can achieve alone.

Purple teaming is a relatively new approach to cybersecurity, but it is gaining popularity as organizations realize the value of combining offensive and defensive strategies. By working together, red, blue, and purple teams can create a more robust and resilient cybersecurity infrastructure.

Here's a comparison of the roles and responsibilities of red, blue, and purple teams in cybersecurity:

It is important to remember that red and blue teams work best when they cooperate and communicate effectively. It's through their combined efforts that organizations can most effectively strengthen their security posture.

What Is the Purple Teaming Assessment and Mitigation Cycle?

The Purple Teaming Assessment and Mitigation Cycle is an iterative process designed to continuously improve and optimize an organization's overall cybersecurity. The cycle involves the integration and collaboration of both red and blue teams to ensure robust and comprehensive security measures.

Figure 3. The Purple Assessment and Mitigation Cycle.

Assess Your Defenses 

The Assessment and Mitigation cycle starts with the red team creating a simulation of potential adversaries. Attack simulations might involve atomic tests, Advanced Persistent Threat (APT) scenarios, malware scenarios, or the use of Breach and Attack Simulation (BAS) solutions. Each of these simulations is designed to mimic real-world cyber-attack techniques.

The primary purpose of a red team involves identifying potential attack paths that adversaries could utilize to compromise an organization's systems and networks. Simultaneously, they uncover gaps in the organization's defenses and assess the effectiveness of the existing security controls.

Measure Your Coverage

The findings of the red team's exercises are documented in a comprehensive report, which is handed off to the blue team. The blue team uses this information to conduct a risk assessment, evaluating and prioritizing which vulnerabilities need immediate attention.

Notably, it's recognized that complete elimination of cyber risk is impossible. The concept of residual risk comes into play, which refers to the level of risk that an organization is willing to tolerate.

Mitigate by Tuning Your Defenses 

The blue team is responsible for analyzing the log data generated by the security controls. If they uncover evidence of successful adversary activity that wasn't recorded, adjustments to the security controls are made, or necessary prevention and detection signatures are added. This ensures the collection of appropriate log data for future detection. Similarly, if adversary activity is indicated in the log data, the team sets up the security controls to prevent or detect such attacks going forward.

Once the blue team has completed its risk assessment and mitigation processes, the cycle repeats. The red team re-runs its adversary emulation, this time evaluating the updated defenses. 

The continuous cycle of assessment and mitigation enables both the red and blue teams to stay ahead of the evolving threat landscape. Purple teaming, by facilitating this cycle, helps organizations build and maintain the best possible defense.

What Are the Challenges of Purple Teaming?

Purple Teaming challenges encompass managing limited time and resources, prioritizing diverse adversary tactics and security gaps, and customizing mitigation and detection strategies to fit specific security controls.

a. Limited Time and Resources

The process of red teams simulating hundreds of adversary Tactics, Techniques, and Procedures (TTPs) is both time-consuming and resource-intensive. Furthermore, the rapidly changing cyber threat landscape necessitates swift responses from threat intelligence (TI), red, and blue teams. These limitations make it challenging for organizations to manage continuous improvement-based processes and maintain a high level of coordination between such as red, blue, and TI teams.

b. Prioritizing Gaps and Adversary TTPs

Achieving full coverage of adversary TTPs or MITRE ATT&CK techniques is neither realistic nor pragmatic for security teams. Thus, red and blue teams need to prioritize TTPs and gaps in their defense strategies, further complicating the task of preventing and detecting these TTPs.

c. Developing Actionable Mitigation and Detection Strategies

While there are resources available that provide generic mitigation and detection recommendations, these often cannot be directly implemented in security controls. This requires teams to adapt and customize these strategies, adding an additional layer of complexity.

Purple Teaming with Breach and Attack Simulation (BAS)

Purple Teaming with Breach and Attack Simulation (BAS) explores the intersection of advanced cybersecurity practices and automated testing. 

This innovative approach enhances the collaborative efforts of red and blue teams (collectively known as the purple team) by automating adversary emulations, continuously testing various security controls. It highlights the dynamic and proactive nature of BAS, emphasizing its role in helping organizations stay resilient and adaptive to the ever-evolving threat landscape.

a. Automating Threat Intelligence with BAS

Breach and Attack Simulation (BAS) provides actionable threat intelligence, which is particularly beneficial for purple teaming. Through threat profiling, relevant threats to an organization's industry and location are identified. 

Figure 4. Threat Profiling for Purple Teaming.

In addition, BAS keeps track of emerging threats and offers actionable mitigation recommendations, enabling teams to respond quickly.

Automating Adversary Emulation with BAS

In the context of purple teaming, Breach and Attack Simulation (BAS) offers a significant advantage by automating adversary emulations. These simulations rigorously test the organization's defense infrastructure, including but not limited to  

• Next Generation Firewalls (NGFW), 

• Web Application Firewalls (WAF),

• Intrusion Detection and Prevention Systems (IPS & IDS), 

• Endpoint Detection and Response (EDR) solutions, 

• Email Gateway solutions,

• AntiVirus and Anti-Malware solutions,

• Extended Detection and Response (XDR) technologies, 

• Data Loss Prevention (DLP) solutions, 

• Security Information and Event Management (SIEM) systems.

The emulations use predefined adversary scenarios, while also providing flexibility to incorporate custom scenarios, ensuring comprehensive security testing.

Figure 5. Automating Adversary Emulation with BAS for Purple Teaming.

Integral to purple teaming, BAS supports running these emulations either on-demand or continuously. This feature allows the purple team to stay adaptive and resilient, thereby maintaining the organization's security posture in sync with the ever-evolving threat landscape.

Automating Security Gap Analysis with BAS

BAS platforms offer continuous adversary emulation and security posture validation, facilitating gap analysis in security controls. By aggregating the results of adversary emulations, BAS identifies and reports the gaps in the tested defense infrastructure, offering a clear picture of the organization's security posture.

Actionable Detection and Mitigation with BAS

Purple teaming, when enhanced with Breach and Attack Simulation (BAS), significantly contributes to mitigating security gaps within an organization's preventive and detective security controls. 

• Fixing Gaps in Preventive Security Controls: 

BAS supports purple teams in addressing gaps in preventive security controls by enabling prevention signatures for threats that slipped through during the simulation phase. It presents a comprehensive library of specific prevention signatures, empowering the team to tailor defenses based on the organization's unique requirements and the security products it uses.

• Fixing Gaps in Detective Security Controls: 

On the detective end, BAS assists in fine-tuning Security Information and Event Management (SIEM) and Endpoint Detection and Response (EDR) systems. It aids in resolving logging gaps and improving detection and alerting capabilities of these systems. Purple teams can use this assistance to elevate log visibility and single out necessary log sources for inclusion in the SIEM or EDR. This helps in the detection of advanced threats.

• Mitigate with Detection Rules

Finally, BAS platforms provide detection rules for all threats in the Threat Library. This set of rules supports the purple team in ensuring comprehensive threat coverage. It includes both vendor-specific and vendor-agnostic rules, each one being regularly tested for false positives. Platforms such as Picus further enhance this capability by offering specific SIEM & EDR detection rules and vendor-agnostic SIGMA rules.

Overall, BAS automates many aspects of the purple teaming process, making it more efficient, consistent, and comprehensive. This continuous and automated approach helps organizations improve their security posture, identify and close security gaps more quickly, and respond more effectively to real-world threats.