Purple Team Exercises: Attack Simulation & Detection Validation
How purple teaming collapses the red/blue feedback loop, MITRE ATT&CK-scoped exercises, Atomic Red Team, detection gaps, and breach and attack simulation (BAS).
Learning Objectives
- → Explain how purple teaming differs from separate red team and blue team engagements
- → Use MITRE ATT&CK technique IDs to plan a structured attack simulation
- → Explain the purpose of tools like Atomic Red Team for repeatable technique execution
- → Identify a detection gap and describe the collaborative process for closing it
- → Explain breach and attack simulation (BAS) as continuous, automated purple teaming
Purple Teaming: Collaboration, Not Just Two Separate Teams
A traditional red team engagement runs stealthily, with the blue team unaware, to test detection under realistic conditions — valuable, but slow to produce actionable detection improvements. Purple teaming flips this: red and blue teams work together in real time, executing one specific technique, immediately checking whether it was detected, and iterating on the detection rule if it wasn't — collapsing the feedback loop from weeks to minutes.
Structuring an Exercise Around MITRE ATT&CK
A purple team exercise is typically scoped to specific ATT&CK technique IDs rather than an open-ended "hack the network" mandate:
- Pick a technique (e.g. T1003.001 — OS Credential Dumping: LSASS Memory)
- Red team executes it in a controlled, scoped way
- Blue team checks: did any existing detection fire? If not, why not?
- Blue team writes or tunes a detection rule (recall the Blue Team Detection Engineering lesson's Sigma rule workflow)
- Red team re-executes the exact same technique to confirm the new detection actually fires
This produces a concrete, measurable outcome per technique — detected/not detected — rather than a single end-of-engagement report.
Atomic Red Team: Small, Repeatable Technique Tests
Atomic Red Team is an open-source library of small, individually-executable "atomic tests," each mapped to a specific ATT&CK technique — instead of running a full multi-stage attack chain, a purple team can execute exactly one technique in isolation, observe the detection result, and move to the next, building a technique-by-technique coverage map.
Finding and Closing a Detection Gap
A detection gap is any technique that executes successfully with no corresponding alert. Closing one typically means:
- Confirming the right log source is actually being collected (a detection can't fire on telemetry that was never ingested)
- Writing or adjusting a Sigma-style rule with more accurate matching logic
- Re-testing the exact same technique to confirm the gap is now closed, not just "probably fixed"
Breach and Attack Simulation (BAS): Purple Teaming, Continuously
BAS platforms automate the purple team loop — continuously and safely executing a large library of known attacker techniques against production (or production-like) environments, and reporting which ones were detected, on an ongoing schedule rather than a one-time engagement. It's the natural evolution of manual purple teaming into something closer to continuous integration testing, applied to detection coverage instead of code.
Common Pitfalls
- Running a purple team exercise but never actually updating any detection based on the results, wasting the exercise's entire value
- Treating a single successful detection test as permanent, when environment/log-source changes can silently break it later (a case for BAS's continuous nature)
- Scoping an exercise so broadly ("simulate a full APT campaign") that specific technique-level detection gaps get lost in the noise
- Running only in disconnected red-team-then-blue-team-report phases, missing purple teaming's actual value: the tight, real-time feedback loop
The feedback loop between attack execution and detection tuning is what actually separates purple teaming from a traditional sequential engagement.
What is the key operational difference between purple teaming and a traditional sequential red-team-then-report engagement?
A technique-scoped exercise produces one clear detected/not-detected answer, rather than a single vague summary at the very end.
Why scope a purple team exercise to a specific ATT&CK technique ID rather than an open-ended 'hack the network' mandate?
BAS runs the same detect/iterate loop on an ongoing automated schedule instead of as a single scheduled event.
How does breach and attack simulation (BAS) relate to manual purple teaming?
💪 Exercises & Challenges
Purple Team Exercises: Attack Simulation & Detection Validation MCQ
Test your understanding of Purple Team Exercises: Attack Simulation & Detection Validation.
Plan a Purple Team Exercise for a Specific Technique
Design a purple team exercise plan for MITRE ATT&CK technique T1110 (Brute Force). Specify: which log source(s) must be collected, what the red team will execute, what the blue team will check for, an
Diagnose Why a Correct Rule Didn't Fire
A purple team exercise targets T1059.001 (PowerShell). The red team executes an encoded PowerShell command exactly matching the pattern from the earlier Blue Team Detection Engineering lesson's Sigma