Purple Teaming

Purple teaming is a way of running offensive and defensive security work together so that each improves the other. The name comes from combining the red team, which emulates attackers, and the blue team, which defends, into a single collaborative exercise. Instead of the red team quietly succeeding and reporting results at the end, the two teams work side by side, replaying attack techniques so the defenders can see exactly what each one looks like and whether their tools detect it.

The purpose is to close the loop between attack and defence. A traditional red team engagement answers whether an attacker could achieve an objective, but it does not, by itself, teach the defenders how to catch that attacker next time. Purple teaming makes detection improvement the explicit goal. As the red team executes a technique, the blue team checks whether it generated an alert, why it did or did not, and what detection to build or tune so that it will be caught in future.

A purple team exercise is usually structured around a framework such as MITRE ATT&CK, which provides a shared catalogue of adversary techniques. The teams work through relevant techniques methodically: the red team performs each one, the blue team observes the telemetry and detection response, and together they record coverage and gaps. The output is a concrete measure of which techniques are detected, which are not, and a prioritised list of detections to improve.

The value is practical and measurable. Organisations frequently discover that their expensive detection tooling misses techniques they assumed it covered, and purple teaming reveals exactly where. Because the improvements are validated on the spot, the exercise produces detections that are known to work rather than theoretical rules. Over successive exercises, detection coverage across the ATT&CK matrix can be tracked and steadily increased.

Purple teaming can be a discrete exercise or an ongoing collaborative practice, and it is often the debrief phase of a red team operation rather than a wholly separate activity. Either way, it suits organisations that already have some detection capability and want to make it demonstrably better, rather than those who have not yet established basic monitoring.

Purple teaming can be run as a discrete exercise or embedded as the debrief phase of a red team operation, and increasingly as an ongoing collaborative practice. However it is structured, its distinguishing feature is measurement: rather than a pass or fail, it produces a concrete, technique-by-technique picture of what the defenders can and cannot see, tracked against a framework like MITRE ATT&CK so that coverage can be improved and re-measured over successive rounds.

Every Precursor red team operation includes a purple team debrief, replaying each stage with the defenders so that every engagement leaves the organisation with improved, validated detection rather than only a list of findings.