Purple Team Approach

Expanded Definition

A purple team approach is not a single team, tool, or process. It is a working model that deliberately combines offensive testing and defensive validation so that each finding is translated into a detection, a control improvement, or a response action. The value lies in the collaboration: instead of treating red team activity as a standalone exercise and blue team operations as a separate function, both sides share context, timing, and outcomes.

In security governance terms, the model is closest to an operational feedback loop. It is commonly used in attack simulation, detection engineering, incident response tuning, and control validation. A mature implementation can map findings to NIST SP 800-53 Rev 5 Security and Privacy Controls so that test results are tied to specific safeguards rather than left as informal observations. Guidance varies across vendors and service providers because no single standard governs purple teaming as a formal discipline yet, so organisations define scope differently depending on their goals.

The most common misapplication is treating purple teaming as a one-time assessment report, which occurs when organisations confuse collaborative validation with a periodic penetration test.

Examples and Use Cases

Implementing a purple team approach rigorously often introduces coordination overhead, requiring organisations to weigh faster detection improvement against the time needed to synchronise testers, analysts, and control owners.

• An adversary emulation exercise where the offensive tester runs a phishing-to-payload chain while defenders tune email, endpoint, and identity detections in real time.
• A cloud intrusion scenario where the team validates alerting across identity, workload, and logging layers, then updates response playbooks after each control gap.
• An CISA Known Exploited Vulnerabilities Catalog-driven exercise that prioritises known-exploited weaknesses and checks whether the organisation detects exploitation quickly enough to contain it.
• An incident simulation where the red and blue teams compare notes during the exercise, allowing analysts to refine detection logic before the same path is repeated at scale.
• A privileged access scenario where the team verifies whether alerting, logging, and approval workflows expose misuse of administrative access quickly enough to trigger response.

Used well, the approach makes security testing actionable instead of theoretical. It also helps translate lessons from frameworks such as the MITRE ATT&CK framework into concrete telemetry and response improvements, even though ATT&CK itself describes techniques rather than the collaborative process.

Why It Matters for Security Teams

Security teams often discover that controls look effective on paper but fail under realistic attack paths. A purple team approach matters because it exposes where monitoring, detection engineering, escalation, or containment breaks down when tested against actual adversary behaviour. That is especially important in environments where identity systems, cloud services, and automation tools are tightly coupled, because a missed alert in one layer can quickly become a broader compromise.

For governance and assurance, the model supports repeatable validation of control effectiveness rather than simple compliance checking. It can also improve cross-functional language between offensive specialists, SOC analysts, incident responders, and platform owners. In practice, the process often depends on structured response expectations drawn from guidance such as NIST incident response guidance and on disciplined control ownership, because findings only matter when someone is accountable for remediation.

Organisations typically encounter the true cost of poor purple teaming only after a live intrusion reveals that a test passed without producing any usable detection, at which point the approach becomes operationally unavoidable to address.

Related resources from NHI Mgmt Group

• How should security teams govern AI agents in purple team exercises?
• How should security teams run purple team exercises continuously instead of as one-off tests?
• Why do one-time purple team exercises create false confidence?
• How should organizations approach the governance of AI agents?