For years I watched red teams and blue teams operate like two departments in the same building who never actually spoke to each other. The red team would break in, write a report, and disappear. The blue team would read the report weeks later, half-understand it, and try to patch what they could. Nobody was really getting better, just busier. That’s the exact problem purple teaming was built to solve, and it’s why I think it’s one of the most practical shifts in modern cybersecurity.
In this guide I’ll walk through what purple teaming actually is, how it differs from red and blue teaming, how to run one, and the mistakes I see teams make when they try it for the first time.
What Is Purple Teaming?
Purple teaming isn’t a separate team with its own headcount. It’s a collaborative exercise where the attackers (red team) and defenders (blue team) work together in real time, sharing techniques, watching detections fire (or fail to fire), and tuning defenses on the spot. The “purple” is literally red plus blue — it’s a mindset and a process, not an org chart box.
Instead of a red team quietly running an engagement for two weeks and dropping a PDF at the end, a purple team session looks more like:
- Red team announces the technique they’re about to run (e.g., a specific MITRE ATT&CK technique).
- Blue team watches their SIEM, EDR, and logs in real time.
- Both sides confirm whether the technique was detected, partially detected, or missed entirely.
- If it was missed, they fix the detection rule together, then re-run the technique to confirm it now fires.
Purple Team vs Red Team vs Blue Team
| Team | Role | Goal |
|---|---|---|
| Red Team | Simulates real attackers | Find gaps before adversaries do |
| Blue Team | Defends, monitors, responds | Detect and stop the red team |
| Purple Team | Bridges red and blue | Turn findings into working detections, fast |
The key difference is feedback loop speed. Traditional red teaming has a feedback loop measured in weeks. Purple teaming compresses that to minutes or hours.
sequenceDiagram
participant Red as Red Team
participant Blue as Blue Team
participant SOC as Detection Stack
Red->>SOC: Execute technique (e.g. T1059 - Command Execution)
SOC-->>Blue: Alert fires or stays silent
Blue->>Red: Report detection result
Red->>Blue: Explain technique details
Blue->>SOC: Tune detection rule
Red->>SOC: Re-run technique
SOC-->>Blue: Confirm alert now fires
Why Purple Teaming Matters
I’ve found three concrete benefits every time I’ve run or observed a purple team exercise:
- Faster detection engineering. Instead of guessing which rules to write, defenders build detections against real, confirmed attack behavior.
- Shared vocabulary. Red and blue teams start speaking in the same terms, usually mapped to the MITRE ATT&CK framework, which makes reporting to leadership far easier.
- Measurable improvement. You can track detection coverage over time instead of relying on a single point-in-time pentest score.
How to Run a Purple Team Exercise: Step by Step
Step 1: Define Scope and Objectives
Pick a specific threat model — ransomware precursor behavior, credential theft, lateral movement — rather than “test everything.” Vague scope produces vague results.
Step 2: Map Techniques to MITRE ATT&CK
Choose a handful of techniques relevant to your environment. If you’re defending a cloud-heavy stack, prioritize cloud-specific techniques over legacy Windows persistence tricks nobody in your org uses.
Step 3: Execute and Observe Together
Run techniques one at a time, in the same room or the same call, with both teams watching logs live. This is the part most organizations skip, and it’s the part that actually makes purple teaming different from a normal pentest.
Step 4: Tune Detections Immediately
When something is missed, write or adjust the detection rule right then, while the context is fresh. Waiting for a follow-up meeting kills the momentum that makes purple teaming valuable.
Step 5: Document and Repeat
Keep a living matrix of technique → detected/not detected → owner → fix status. Re-run the same techniques quarterly to confirm detections still work after infrastructure changes.
Common Mistakes in Purple Teaming
- Treating it as a one-time event. Purple teaming only pays off when it’s recurring, not an annual checkbox.
- Skipping documentation. Without a technique matrix, you lose the ability to show progress over time.
- Letting red team “win” quietly. The goal isn’t red team bragging rights — it’s blue team improvement. If sessions turn adversarial, the exercise fails.
- Ignoring tooling gaps. Sometimes a missed detection isn’t a rule problem, it’s a visibility problem (no logging source at all). Purple teaming should surface these gaps too.
Best Practices
- Start small — three to five techniques per session is plenty for a first attempt.
- Involve threat intel so technique selection reflects attackers actually targeting your industry.
- Automate detection validation afterward so regressions get caught automatically, not just once a quarter.
- Rotate who leads the session between red and blue so neither side dominates the narrative.
Purple Teaming and Automation
Manual purple teaming works, but it doesn’t scale well across large environments. Many teams now pair purple team exercises with automated breach-and-attack simulation (BAS) tools that continuously replay known techniques and flag detection drift. I see this as an evolution, not a replacement — automation handles the repetitive validation, while human-led purple team sessions handle the creative, novel technique testing that tools can’t yet replicate. If you’re building out broader security automation for incident response, this pairs naturally with purple team findings.
FAQs
Is purple teaming the same as a penetration test? No. A pentest is typically red-team-only and report-driven. Purple teaming is collaborative and focused on improving detection in real time.
Do I need a dedicated purple team? Not necessarily. Most organizations run purple team exercises using their existing red and blue resources rather than hiring a separate team.
How often should purple team exercises run? Quarterly is a reasonable starting cadence, with more frequent sessions around major infrastructure or detection stack changes.
What tools are used in purple teaming? Common tools include Atomic Red Team for technique execution, MITRE ATT&CK Navigator for mapping coverage, and whatever SIEM/EDR platform your blue team already relies on.
Conclusion
Purple teaming works because it kills the wall between the people who find gaps and the people who close them. It’s not about a new team or a new budget line — it’s about getting red and blue in the same room, watching the same logs, and fixing things while the context is still fresh. If your organization runs red team engagements today but treats the findings as a PDF that gathers dust, that’s the exact gap purple teaming was designed to close. Start with one small exercise, three techniques, one afternoon, and you’ll already see where your detection stack quietly falls short.
