How to Ensure Your Purple Team Fails Miserably

You Treated It as an EDR Benchmark

Pick your poison. Either you measured success purely by whether your EDR fired an alert, or you skipped host-based testing entirely because “EDR will catch it.”

I watched a team spend three hours troubleshooting why their endpoint tool missed suspicious LDAP traffic that returned a list of Kerberoastable users. They had only ever tested if their network monitoring tools could see the exact kinds of patterns produced by BloodHound, not boring, manually crafted LDAP queries from ADSearch.

I also had a client decide not to pursue other on-host testing because their EDR caught vanilla Mimikatz.

Of course it did. It has for years. Meanwhile, none of them had considered that running Task Manager as Administrator to accomplish the same LSASS dumping goal should catch someone’s eye.

This does not count as testing your security program. You’re just testing whether a vendor’s signatures still work.

You Can’t Write Your Own Detections

If your entire detection capability is vendor-provided rules, you don’t have a detection capability. You have a subscription.

Even half-decent attackers don’t match signatures. They use living-off-the-land binaries, legitimate admin tools, and techniques that look like normal operations until you understand the context. When I simulate something that doesn’t trip a vendor rule — and that’s most things — the response is usually “nothing we could do.”

There’s always something you could do. You just never built the muscle to do it.

You Had No Idea What to Test

I’ve kicked off engagements where the client’s answer to “what threats are you most concerned about?” was a shrug. No threat intelligence, no prioritized list of techniques, no understanding of what adversaries actually target their industry.

So we tested whatever seemed interesting. The results showed gaps in techniques that didn’t matter to their actual risk profile. We validated defenses against nation-state tradecraft when ransomware groups were the real threat. Everyone felt productive, but nothing notably useful happened.

The Report Went to SharePoint to Die

I’ve watched six-figure engagements produce reports that never left their PDF form.

No one prioritized the findings by impact or stuck them in a ticketing system to at least appear like they were interested in improving. Without a framework for improvement, every finding is equally important — which means none of them are.

Without an improvement strategy, your analysts will context-switch between “we can’t detect Kerberoasting” and “we need better phishing detection” until they burn out or quit, and you still have both problems.

You Thought Buying Tools Was the Same as Using Them

This one’s universal, but it’s especially lethal here.

Lots of companies buy adversary detection platforms and never configure them. Admittedly, “no configuration needed” is a strong selling point, but if that also means “no configuration possible,” the vendor is just saying “trust me, bro” and you’re believing it.

Money spent does not equal security achieved. Tools require people and process. If you don’t have both, you have expensive shelfware.

We Sold “Purple Team” Without Defining It

The definition of “purple team” is loose enough that sales can pitch almost anything under that label.

I can’t count the number of times sales promised what was effectively a red team ride-along where the client could fix things along the way. That is not a collaborative security improvement exercise. That is a field trip.

We, the red team, showed up ready to collaborate on running attacks and building detections, only to get stuck eating the cost of the sales team’s sins and trying not to look incompetent while we “red team” the client over a screen share.

The client ended up watching us work instead of working with us.

Worst of all, purple team engagements are so commonly shorter than red team engagements that the client ends up getting a condensed red team exercise for a huge discount. Putting your practitioners under immense pressure to compress a red team exercise into a purple team timeline makes them miss things, burn out, and resent the whole enterprise.

This happens constantly. “Purple team” means different things to different people, and by the time the practitioner gets involved, the contract is signed and the sales rep has moved on to the next deal.

We Skipped the Hard Scoping Questions

It’s uncomfortable to ask “what’s your detection maturity?” when the answer might be “we don’t really have any.” But if you deploy custom malware against a team that doesn’t have EDR, or test for advanced persistence against a team that can’t detect a whoami command, you’ve wasted everyone’s time.

The engagement should meet the client where they are. That requires asking questions that might make the deal smaller, or even turn it into another project entirely.

Plenty of purple team clients need to be talked down to a penetration test, but that’s not as profitable.

We Over-Engineered Instead of Just Running Attacks

Consulting outfits all share this weird curse where they have to constantly optimize to squeeze just a little more profit margin out of a good thing.

I’ve watched consulting teams spend months and months building the ultimate purple team platform, only to never finish it. Every technique automated. Every detection templated. Every report auto-generated.

Meanwhile, real attackers were just opening PowerShell and nobody had validated whether anyone would notice.

The most effective purple teams start with documented attacker tradecraft — the actual commands from real incident reports, MITRE ATT&CK, or even a recent pentest — and see what happens.

Sometimes that’s a Python script, and sometimes it’s literally typing commands into a PowerShell window. The tooling is secondary to the outcomes.