Summary
A purple team exercise puts red and blue teams in the same room, working in parallel, so detection gaps get found and fixed during the engagement instead of buried in a report afterward. This article walks through what a real purple team simulation looks like in practice: an insider threat scenario that moves through endpoint infiltration, persistence, network reconnaissance, and privilege escalation, showing exactly what attackers look for and what defenders need to catch it.
What Is a Purple Team Engagement?
Most organizations are familiar with penetration testing. A red team comes in, probes your environment and produces a report. You read the report, prioritize the findings, then remediate.
The problem is that all the learning happens after. By the time the report lands, the team that would benefit most from understanding the attack often wasn't in the room when it happened.
A purple team exercise changes that structure. Red and blue work in parallel with the client present throughout. As the red team executes techniques, the blue team is watching the logs, reviewing forensic artifacts, and identifying in real time where detections fire and where they don't.
If a security rule isn't configured correctly, that gets addressed during the engagement. If a detection fires too late to matter, that becomes an immediate conversation.
In a purple team exercise, the learning doesn't wait for a report, it happens while the attack is still in progress.
Who Should Be Running Purple Team Exercises?
The target profile for a purple team exercise is any organization with an internal SOC or an MSSP handling detection and response. Company size is not generally a determining factor; purple team engagements work for small organizations and for companies exceeding 40,000 employees alike. What matters is whether a detection and response program exists to stress-test.
For organizations in industrial or manufacturing environments, OT infrastructure often becomes a focal point. If detection capabilities extend to those environments, there's real opportunity to surface gaps that would otherwise go unexamined.
How the Simulation Unfolds
A purple team simulation follows the same general sequence a real attack would: an attacker gets in, makes sure they can stay in, figures out what's around them, and then works to gain more access than they started with. Breaking the engagement into these four phases gives both teams a clear way to track where the simulated attacker is at any given point and what kind of detection should be catching them there.
Phase 1: Endpoint Infiltration
Every purple team engagement starts with a scenario tailored to the client's specific business and risk profile, since not every organization faces the same kind of threat. Once a way in has been established, the red team's first goal is getting a foothold on an endpoint without triggering an immediate response.
That typically means disguising malicious activity as something routine: a file that looks like a normal download, traffic that resembles ordinary web activity, or access patterns that don't follow an obvious, repeatable schedule.
The goal isn't to be invisible forever, but to look unremarkable for long enough to get established.
What the blue team sees: This is usually where the first gap shows up. Activity that should raise a flag often doesn't, because it's been deliberately shaped to resemble something normal. It's a direct demonstration that a single security tool looking for known threats isn't enough on its own.
Phase 2: Establishing Persistence
Once the red team has a foothold, the priority shifts to making sure it doesn't lose it. That usually means setting up so access survives a reboot, a logout, or routine IT activity, often by attaching the malicious activity to something the system already trusts and runs regularly.
What the blue team sees: The blue team often discovers that existing detection rules are watching for the wrong thing, flagging a familiar process by name without paying attention to where or how it's running. Seeing that gap play out live, rather than reading about it after the fact, tends to make the fix more clear than a report.
Phase 3: Network Reconnaissance
With a foothold established, the red team's next move is figuring out what else is reachable. This usually means quietly mapping the environment: what other devices and systems exist, how they're connected, and where there might be an opportunity to move further in.
A common finding here is that the tools needed to do this reconnaissance are often already available and approved for legitimate use by the organization's own IT team.
What the blue team sees: A tool the organization already trusts and uses internally can be the same one being used against it, with no new software and nothing unusual introduced. That overlap is exactly why visibility into who's using approved tools, and from where, matters as much as having the tools in the first place.
Phase 4: Privilege Escalation
At this point, the red team typically only has the access level of a standard employee account. The goal becomes finding a way to gain broader access without doing anything that would set off alarms.
What's notable is how rarely this requires anything sophisticated. In practice, the path forward often already exists: credentials sitting somewhere they shouldn't be, old accounts that were never cleaned up, or systems that were simply never brought into the organization's security monitoring in the first place.
What the blue team sees: This phase tends to produce the most direct "we had no idea that was there" moments. The blue team gets a precise, current list of exactly which accounts, devices, and permissions need attention right away.
What This Reveals
One of the most consistent benefits of running a purple team exercise is seeing detection thresholds made visible. It's one thing to know a detection exists. It's another to watch it trigger after an attack has already completed and the attacker has moved to the next phase.
That visibility is hard to produce any other way. A penetration test report can describe a gap, but only a purple team exercise shows a security team exactly where that gap lives in their own environment, in real time, with offensive and defensive expertise both in the room to address it.
See It for Yourself
Reading about how a purple team exercise works is useful. Watching one unfold is better. Echelon recently walked through a live simulation covering everything in this article and more, available now as an on-demand recording.
If your organization has a detection and response program and you're ready to find out how it holds up under real adversarial pressure, Echelon's purple team engagements are built to show you exactly that. Learn more about our Purple Team services.