It was 3:12 AM. While the log flow usually had a hypnotically stagnant vibe, an unusual 'User Enumeration' alert popped up on testCompany’s SOC panel. Normally, as the Red Team, when we tried something, we’d expect the Blue Team to catch it within 15 minutes. But this time, something was off: the alert fired, but nobody knew what to do. On the Red Team side, we had already breached the perimeter, generated a 'Golden Ticket,' and were roaming around with Domain Admin privileges. The Blue Team could only say 'something is happening.' That was the moment I realized: just attacking or just defending isn't enough; we have to build that missing bridge—Purple Team operations.
The Cold War Between Silos
For years, the cybersecurity world has been split into two camps: the Red Team saying 'We’ll get in, you can’t stop us,' and the Blue Team saying 'You’re attacking, but we see everything.' Sometimes this rivalry gets so intense that teams avoid sharing information, turning it into an ego war. But the real world isn't a CTF competition, my friend. When a real APT actor knocks on your door, it doesn't matter how smart the Red Team is or how fast the Blue Team reacts in isolation. If these two teams aren't synchronized, the organization is always one step behind.
Purple Team is more of a methodology than a team. It’s the art of mapping attack techniques (TTPs) to defensive capabilities. Red Team attacks, Blue Team monitors; then they come together and ask, 'What did you do here, and why couldn't I see it?' This process strengthens defensive layers with real-world data.
A Technical Glimpse: Kerberoasting and the Detection Gap
Let's examine this process through a technical scenario. Suppose we are simulating a 'Kerberoasting' attack on the testCompany network. Our goal is to pull the tickets (TGS) of accounts with a Service Principal Name (SPN) registered and crack them offline.
Red Team (Attack Phase - Defanged): Imagine I run the following command after infiltrating the network as an attacker:
# Defanged Kerberoasting Payload
# Purpose: Requesting a TGS ticket for a specific SPN
Add-Type -AssemblyName System.IdentityModel
New-Object System.IdentityModel.Tokens.KerberosRequestorSecurityToken -ArgumentList "HTTP/web-server-01.testcompany.local"
When this command runs, an Event ID 4769 (A Kerberos service ticket was requested) is generated on the Domain Controller.
Blue Team (Defense Phase): If the Blue Team is only monitoring 'Successful Login' (Event ID 4624) logs, they will miss this attack entirely. During a Purple Team exercise, the Red Team runs this command and asks the Blue Team: 'Look, I just requested a ticket; what showed up on your screen?'
The Blue Team checks their panel and realizes that 4769 logs create too much 'noise,' causing this specific alarm to be overlooked. This is exactly where the 'Purple' touch begins.
Detection Engineering
During the Purple Team meeting, the following decision...