How do you balance the time and resources between purple team security testing and other security activities?

Furthermore, by defining a scope you can measure the effort required to execute the task, making it possible to evaluate and measure the time spent until the activity is completed. But to do this, the processes must be fully defined and organized, especially asset management, understanding the attack surface and well-structured security technologies, so you can select the most appropriate scope for testing.

In my experience, a purple team is most effective when the specific scenarios are determined as early in the process as possible. It can be a specific system, LAN segment, a single server or web app, or physical breach exercise. In all cases, purple team is the most resource heavy ask of a client. Everyone needs to be "in the know" and collaborating for this to be successful. So, it is critical that the timeline be agreed to and that all stakeholders are able to support during that timeframe.

Your scope keeps you on track. When pulling threads, it's easy to find yourself off the beaten path and down a rabbit hole. Look back up and make sure you haven't drifted out of scope to ensure your staying on tracking and making effective use of the engagement time. Flag those interesting threads for later, but don't let blinders lock you into something that isn't going to help reach your end goal.

Before starting purple team security testing, clearly define your objectives and scope to align with business goals. Determine if you aim to test a specific system, process, or scenario, validate a hypothesis, verify a control, or challenge an assumption. Decide whether to focus on technical, operational, or strategic aspects to prioritize activities and set realistic expectations.

As a cybersecurity professional who has led numerous purple team security testing engagements, I understand the critical importance of allocating roles and responsibilities effectively. For instance, in a recent purple team exercise, I ensured that the red team members were tasked with simulating real-world attack scenarios, while the blue team focused on detecting and responding to these simulated threats. Additionally, by involving stakeholders from various departments, such as management, development, and auditing, we fostered a collaborative environment where insights from different perspectives were leveraged to enhance our overall security posture.

The best purple teams are coordinated and executed in a slow, systematic manner. Purple teams are about the efficacy of controls and the learning that happens. They should be open in nature and guided by some core principles including; -collaboration -precise determination of scope -open consideration of what should be in scope -leveraging tacit knowledge of all players -tight coordinating -modelling TTPs and establishing threat models -executing precise and considered attacks -measuring response detection and error -learning together as multi disciplinary teams Great purple teams drive serious results. They take energy and effort. Where we can, slow them down. They are real learning exercises that can drive tremendous value.

Understanding your team's current scenario, especially with regard to tasks, is fundamental, defining responsibilities and realistic deadlines so that the team can prioritize and execute, for this it is necessary to have a very clear scope and open communication with the team, whether in weeklys or informal communications.

Many teams have a diverse set of members. Typically, while well rounded, many members have core areas they focus on. Understanding your team members skills and leveraging them appropriately ensures your using the most effective tools for the job. When possible, work in lead and secondary (or sr/jr) roles so you are always upskilling or training the group. Leverage the concept of "Judds Box" to allow junior members the ability to grow effectively and gain autonomy within their roles.

In Purple team security testing, the Red Team focuses on simulating attacks, the Blue Team handles defense and detection, and both collaborate on planning, execution, analysis, and reporting. Management oversees the process, developers address identified vulnerabilities, and auditors ensure compliance. Clear communication channels and escalation procedures are essential to avoid confusion and ensure accountability.

If we consider purple teaming a learning and error inducing exercise, we are onto something special here. As such it needs to be very carefully coordinated. It can leverage existing spend well - your internal resources are already there and paid for! Scheduling needs to be considered as well executed purple teams take investment. Such investment can provide immense value as we are making sure we have ROI on our money and time investment in controls. As such we want to find the gaps. We want to find error. We want to learn. We have to budget for this but the ROI can drive reduced expenditure elsewhere and where possible should be self funding. Some great purple teams reduce spend on excess controls and tighten what we already have.

When scheduling activities, you divide the team into specific tasks, allocating resources according to each member's expertise. Considering the availability of resources, it decides to carry out the tests in phases, prioritizing critical areas for the business. Check the feasibility of more advanced security tools, weighing the cost-benefit. Choose to invest in technologies that help identify vulnerabilities more efficiently, maximizing the value of testing.

For me, as a pen test solution architect, I usually have to semi-commit to a budget and schedule based off the client's requirements. The best way to do this, I've learned, is with time boxing. Meaning, offering 4, 6, 8, or 12 week purple team engagements. As part of the schedule the first 1 or 2 weeks is dedicated almost entirely to planning and agreeing on the exercises that provide the most value or meet the clients business needs. With that, the subsequent exercises can be scheduled for the remainder of the contract. This mean stakeholders are only keyed up when needed vs the entire purple team contract.

For effective purple team security testing, schedule and budget your activities based on objectives, scope, and available resources. Consider potential operational impacts, like downtime or disruptions. This approach optimizes resource use, minimizes risks, and maximizes value.

Purple team security testing is an ongoing process of iterative and adaptive testing, where tactics, techniques, and procedures are adjusted based on feedback and results from each cycle. Documenting findings, recommendations, and actions, and sharing them with relevant parties enhances security maturity, identifies new threats and vulnerabilities, and implements effective countermeasures.

Iterative and adaptive testing lies at the heart of successful purple team security testing initiatives. In my experience, embracing a continuous improvement mindset has been instrumental in driving meaningful outcomes. For example, during a recent purple team engagement, we conducted multiple iterations of testing cycles, each building upon the insights gained from the previous cycle. By adapting our tactics, techniques, and procedures based on the evolving threat landscape and our own learning experiences, we were able to stay ahead of emerging threats and bolster our defenses effectively.

In the first cycle, the team identifies a vulnerability in the online login system. Instead of simply fixing the problem, you adopt a more iterative approach, adjusting the test, simulating different attack scenarios, and recurrently improving techniques to assess the system's resistance against specific threats. This way, you can adapt the blue team's defense mechanisms and the Purple Team, obtaining insights as each threat is detected.

By integrating this activity into your overall security program, you collaborate with your compliance team to ensure testing is aligned with industry regulations. You also connect to risk management to identify potential impacts and prioritize the most critical areas to test. Furthermore, you can evaluate points that may also affect privacy regulations and evaluate the company's incident response plan, not just focusing on what the Red Team can do in relation to attack scenarios and what the Blue Team can detect based on these scenarios, so the test even covers a business level and helps guide investments in cybersecurity.

Incorporating this activity into your overarching security program necessitates close collaboration with the compliance team to ensure testing remains compliant with industry regulations. Engaging with risk management aids in identifying potential impacts and prioritizing critical testing areas. Moreover, assessing points that could impact privacy regulations is imperative, alongside evaluating the efficacy of the company's incident response plan. Beyond Red Team attack simulations and Blue Team detection exercises, the testing extends to a business-level assessment, guiding cybersecurity investment strategies. This comprehensive approach ensures thorough coverage and strategic alignment with organizational objectives.

Purple team security testing should be integrated with compliance, risk management, and incident response to ensure alignment with security policies, standards, and frameworks. This integration ensures consistency, compliance, and coherence across the entire security program, following best practices and legal guidelines.

Evaluating and improving performance is essential for ensuring the efficacy and relevance of purple team security testing activities. In a recent assessment, I implemented robust performance metrics to measure the effectiveness of our testing efforts. By tracking key performance indicators such as mean time to detect (MTTD) and mean time to respond (MTTR), we were able to identify areas for improvement and implement targeted remediation strategies. Additionally, conducting post-mortem reviews allowed us to capture lessons learned and apply them to future engagements, thereby fostering a culture of continuous learning and enhancement within the organization.

Purple team security testing requires regular evaluation and improvement through metrics, indicators, and feedback. Benchmark performance against objectives and industry standards to identify strengths and weaknesses. This process helps demonstrate value, justify investment, and enhance confidence and credibility.

In addition to the aforementioned best practices, it's imperative to recognize the value of fostering a culture of collaboration and knowledge sharing within the organization. By encouraging open communication channels and facilitating cross-functional collaboration between red and blue teams, as well as other stakeholders, we can leverage collective expertise to address complex security challenges more effectively. Furthermore, investing in ongoing training and development initiatives can empower team members with the skills and knowledge needed to adapt to evolving threats and technologies, ultimately strengthening the organization's overall security posture.

To me, one of the most important things to consider with purple teams, is the time strain it puts on client resources. As someone proposing services, you must be aware of this. As a client requesting services, you must understand this so your team is aware of what may be asked of them. The most successful purple teams are the most collaborative ones!