Purple team exercises are where red and blue teams stop performing at each other and start working with each other. In the traditional model, the red team attacks in secret, writes a report, and the blue team reads it months later — if anyone reads it at all. A purple team exercise collapses that cycle into a single collaborative session: the attack is executed step by step, mapped to MITRE ATT&CK techniques, while defenders watch in real time, check exactly what fired and what did not, and build or fix detections on the spot. This is the field guide to running them well.
#Quick Answer: What Is a Purple Team Exercise?
A purple team exercise is a collaborative security test where offensive (red) and defensive (blue) practitioners execute attacks together in real time — typically mapped to MITRE ATT&CK techniques — while the blue team observes exactly what is and isn't detected. Unlike a penetration test that ends in a PDF, each attack is immediately replayed, detections are built or fixed on the spot, and both teams leave measurably better.
#1. Why Red-vs-Blue Breaks: The Case for Purple
The traditional red-versus-blue model has well-documented failure modes. At MITRE ATT&CKcon 2018, Deloitte's Olaf Hartong and Vincent Van Mieghem laid them out bluntly: red teaming can antagonize defenders, the blue team is often tipped off (or kept in the dark for realism, then handed a report they lack the context to act on), findings arrive as a PDF that nobody operationalizes, exercises run for compliance rather than improvement, and the blue team sometimes lacks the offensive knowledge to follow up on what the report describes. Each of these is a collaboration failure, not a technical one.
Meanwhile, blue teams often hold a shallow understanding of adversary behavior. As AttackIQ's CISO's Guide to Purple Teaming notes, defenders need continuous exposure to the anatomy of real attacks — and interactions with offensive practitioners are among the best ways to get it. Purple teaming fixes both sides at once: the red team learns which of its techniques actually evade the organization's specific controls, and the blue team learns exactly which telemetry and detections failed, with the attacker sitting next to them to explain why.
The effectiveness data backs the model. A CRA survey on adversary attack simulation and emulation, covered by SC World, found that 88% of purple teamers believed their cybersecurity defenses had improved, compared with just 52% of those using penetration testing alone — and nearly 9 out of 10 purple team users called the exercises very effective at defending against ransomware and other advanced attacks. Purple teams were also more likely to convert results into management support for security investment. Collaboration, it turns out, is a strategy for getting budget as well as for getting better.
#2. Anatomy of a Purple Team Exercise
A good purple team exercise follows a repeatable structure, and every phase is joint. It starts with scoping: pick one adversary or one objective, not the whole threat landscape. Threat intelligence drives the choice — emulate an actor relevant to your sector, such as a ransomware affiliate or an initial-access broker, rather than a generic technique list. The TIBER-NL framework, developed for threat-intelligence-based ethical red teaming in the financial sector, recommends playing each scenario phase by phase, from reconnaissance through to wherever the attack ended, so defenders see the full chain rather than isolated tricks.
Next, decompose the scenario into MITRE ATT&CK techniques — the shared language both teams speak. If the scenario involves credential theft followed by lateral movement, the plan names the techniques explicitly: OS credential dumping, remote services exploitation, and so on. This mapping is what makes the exercise measurable later, because each technique becomes a row in your detection coverage matrix.
Execution is where purple diverges from red. The offensive operator runs each technique step by step while the blue team watches its SIEM, EDR, and network sensors live. For every step, both teams record the same verdict: blocked, detected, logged but not alerted, or completely missed. The blue team then tunes, adds a missing log source, or writes a new detection — and the red team replays the technique to confirm the fix works. That tight execute-observe-fix-replay loop is the entire value proposition; without the replay, you have just performed an expensive demonstration.
Include people and process, not only technology. The TIBER-NL purple teaming guidance stresses that sessions should cover the full people-process-technology stack and involve everyone who participated in each phase — including, for a phishing scenario, the compromised users themselves. And scope at least one exercise per year around your APIs: broken object-level authorization and mass assignment remain among the most exploited web flaws, so testing your API authorization controls adversarially belongs in the purple team rotation alongside endpoint and network scenarios.
#3. Tooling: Atomic Red Team, Caldera, and Breach-and-Attack Simulation
You do not need an elite red team to start purple teaming — you need repeatable tooling. Atomic Red Team is the usual entry point: a library of small, self-contained tests, each mapped to a specific MITRE ATT&CK technique, that any practitioner can execute safely in a lab or production-adjacent environment. MITRE Caldera goes further, automating full adversary emulation campaigns so you can replay an entire intrusion chain consistently. Commercial breach-and-attack simulation platforms productize the same idea with scheduling, reporting, and safety guardrails.
Automation matters because purple teaming is a regression discipline, not a one-off event. When the blue team writes a new detection for a missed technique, someone must re-run that technique next week, next month, and after every EDR policy change to confirm the detection still fires. Manual re-execution does not survive contact with busy calendars; scripted atomic tests do. The CRA survey found that most purple teaming users built exercises with a specialized purple teaming platform (89%) or a breach-and-attack simulation platform (80%) — the tooling is what turns an exercise into a program.
Start small regardless of budget: pick five ATT&CK techniques relevant to your top threat, run the Atomic Red Team tests for each, record the detection verdicts, fix the misses, and replay. That single afternoon delivers more defensive value than most week-long engagements.
#4. Measure Coverage, Not Just Findings
The output of a purple team exercise is not a findings report — it is a detection coverage map. Plot every tested technique on an ATT&CK Navigator heatmap, colored by verdict: detected, partially detected (logged but not alerted), or missed. That heatmap is the single most persuasive artifact in defensive security: it shows leadership exactly which adversary behaviors you can see and which are invisible, in a language executives can grasp without a glossary.
Track the metrics that describe defensive performance per technique: detection rate by tactic, mean time to detect for each executed technique, and whether the technique was blocked outright or merely observed. Baseline these numbers in your first exercise and trend them across quarters — the trend is the proof that the program works. SANS research on security operations maturity found that 38.6% of organizations perform red, blue, or purple team exercises as part of cyber-readiness, which means a coverage map also benchmarks you against a meaningful peer group.
Use the exercises to validate architectural assumptions, not just tool configurations. Every technique that bypasses a control is a test of the architecture behind it — and zero-trust architectures in particular benefit from adversarial validation, since their whole premise is that no technique should succeed on implicit trust alone. When a purple team exercise confirms that assumption technique by technique, the heatmap becomes evidence that the architecture works as designed.
#5. The Debrief: Turning Misses Into Detections
The exercise is not over when the attack ends — it is over when the detections ship. Hold the joint debrief within days, while the telemetry is fresh and both teams remember what happened. Walk the heatmap technique by technique, and for every miss or partial detection, answer three questions: what telemetry would have caught this, why was that telemetry missing or unalerted, and who owns the fix.
The fixes fall into predictable buckets. Missing log sources — the classic gap — mean engaging the platform or IT owners to enable the right audit policies, which is a people problem disguised as a technical one. Tuning gaps mean rewriting the detection: narrowing or broadening the logic, adding exclusions for known-good behavior, or correlating with a second signal. Logic gaps mean writing a brand-new detection, ideally as code in a portable format like Sigma so it is versioned, reviewed, and testable. Each new or changed detection then goes back through the replay step from the exercise: re-execute the technique and confirm the alert fires with the right severity and the right context.
Track every fix to closure with the same seriousness as a vulnerability remediation program, because that is what it is. An exercise that produces twenty findings and zero shipped detections was entertainment. An exercise that produces five findings and five validated detections was an improvement.
#6. Cadence and Maturity: From Quarterly to Continuous
Run your first purple team exercises quarterly, each focused on one adversary or one technique cluster. That cadence is sustainable for most teams and produces a visible heatmap trend within a year. As the program matures, automate the replay layer: schedule weekly runs of your atomic test library so that every detection is continuously regression-tested against the current environment, and reserve the quarterly joint sessions for new adversaries, new techniques, and the scenarios automation cannot reach.
Maturity looks like this: ad-hoc exercises become scheduled exercises, scheduled exercises gain automated regression testing, and the whole program becomes adversary-informed — driven by threat intelligence about the actors actually targeting your sector rather than by whatever techniques are fashionable. The CRA survey found that nearly half of organizations had conducted some form of adversary emulation, and that purple team practitioners were the most likely to use results strategically — shaping security strategy and winning resources, not just vetting controls. That is the end state worth aiming for: a purple team program that does not merely test defenses but directs where the security budget goes next.
#Frequently Asked Questions
How is a purple team exercise different from a penetration test?
A penetration test is an independent assessment that ends in a report; the testers find vulnerabilities, write them up, and leave. A purple team exercise is collaborative and iterative: defenders watch each attack technique execute in real time, fix detections immediately, and replay the technique to verify. Pen tests answer "what is vulnerable"; purple teams answer "what can we detect, and how fast" — and then improve the answer.
Do we need separate red and blue teams to start purple teaming?
No. Many organizations start with one or two practitioners playing both roles, using Atomic Red Team tests and validating detections in their own SIEM. What matters is the discipline — execute, observe, fix, replay — not the org chart. Separate teams help at scale, but the methodology works with a single motivated analyst and a lab environment.
Which MITRE ATT&CK techniques should we test first?
Start with the techniques your threat intelligence says adversaries actually use against your sector — typically credential access, execution via scripting, persistence mechanisms, and lateral movement. Then prioritize the techniques protecting your crown jewels: test what guards the data and systems whose compromise would hurt most, before testing the long tail.
Can purple team exercises cover AI systems and agents?
Absolutely, and they should. AI agents with tool-calling abilities are new privileged insiders: prompt injection, excessive agency, and insecure output handling are all testable adversary techniques. Run purple team scenarios against your AI deployments the same way you would against any production system — and review AI agent security fundamentals first so both teams share the threat model.
#Sources and Further Reading
- CRA survey: Purple teams increasingly steer security strategies — 88% of purple teamers report improved defenses versus 52% for pen-test-only: SC World
- AttackIQ: The CISO's Guide to Purple Teaming — building consensus on adversary techniques and running collaborative exercises: white paper
- TIBER-NL Purple Teaming Guide — phase-by-phase purple teaming methodology from De Nederlandsche Bank: AFM
- Deloitte at MITRE ATT&CKcon 2018: From Red vs Blue to Red and Blue — the original case for collaborative teaming: slides
- The CyberWire on the ATT&CK framework — purple team exercises as the prime ATT&CK use case: CyberWire