Disclaimer: This article is provided strictly for educational purposes and authorized security testing. Only run these techniques against systems you own or have explicit written permission to assess. Unauthorized access to computer systems is illegal in virtually every jurisdiction and can carry severe penalties.
Introduction
Purple teaming is a collaborative exercise where offensive (“red”) and defensive (“blue”) teams work together, in real time, to emulate specific adversary techniques and validate whether they are detected and how well they are contained. It differs from a traditional blind red team engagement, where the blue team is not told an exercise is happening and success is measured by whether the red team achieves objectives undetected. Purple teaming instead optimizes for a different outcome: closing detection gaps as fast as possible by removing the element of surprise and turning the engagement into a shared feedback loop.
The value proposition is speed and coverage. A blind red team engagement might surface that lateral movement via WMI went undetected; a purple team exercise runs that same technique, watches the SOC’s tooling in real time, tunes the missing detection on the spot, and reruns the technique to confirm the fix works — compressing what could be a quarter of follow-up work into a single session.
Attack Prerequisites
Running a productive purple team exercise (rather than an unfocused one) depends on having a few things in place beforehand:
- A defined threat model — which adversary or ATT&CK techniques are in scope, usually informed by threat intelligence relevant to the organization’s sector rather than an arbitrary technique list.
- Blue team visibility into the exercise as it runs — access to the SIEM/EDR console in real time, not just after-action log review, so detections (or their absence) are observed as each technique executes.
- Tooling to execute atomic techniques safely — Atomic Red Team, MITRE Caldera, or an equivalent framework mapped to ATT&CK technique IDs, plus a rollback/cleanup plan for anything destructive.
- Stakeholder buy-in and a safe scope — explicit authorization for the systems and techniques involved, and agreement on which atomics are too disruptive to run in production (e.g. ransomware-simulation file encryption tests) versus which are safe.
How It Works
A purple team exercise is organized around the MITRE ATT&CK framework as a shared vocabulary: the red side selects techniques by tactic (e.g. T1003 OS Credential Dumping, T1021.002 SMB/Windows Admin Shares, T1053.005 Scheduled Task) relevant to the threat model, and for each one, executes a minimal, controlled action that reproduces the technique’s detectable behavior without necessarily achieving the full adversary objective. The blue team watches their stack — EDR alerts, Sysmon/Windows Event Log pipelines into the SIEM, network telemetry — and records, for each technique, whether it was detected, at what fidelity, and how long detection took.
Gaps are triaged immediately: if a technique executes cleanly with no alert, the two teams work together to understand why — missing log source, an under-tuned Sigma/EDR rule, or a genuine blind spot in instrumentation — and iterate on a fix before moving to the next technique. This tight loop is the defining characteristic of purple teaming versus a report-then-remediate-later red team model.
Coverage is typically tracked against an ATT&CK Navigator layer: each tested technique is marked detected, partially detected, or missed, producing a heat map that becomes both a report artifact and a prioritized backlog for the detection engineering team.
Practical Example / Configuration
Atomic Red Team ships individual, ATT&CK-mapped test cases as YAML, executed via its PowerShell (or Invoke-AtomicRedTeam) runner. A credential-dumping technique test targeting LSASS (T1003.001):
attack_technique: T1003.001
display_name: OS Credential Dumping: LSASS Memory
atomic_tests:
- name: Dump LSASS.exe Memory using ProcDump
description: |
Uses Sysinternals ProcDump to create a memory dump of lsass.exe,
the classic precursor to offline credential extraction.
supported_platforms:
- windows
executor:
command: |
procdump64.exe -accepteula -ma lsass.exe #{output_file}
cleanup_command: |
del #{output_file} >nul 2>&1
name: command_prompt
input_arguments:
output_file:
description: Path to write the dump
type: Path
default: C:\Users\Public\lsass.dmp
Invoking it and watching for a corresponding EDR/Sysmon alert (process access to lsass.exe with GrantedAccess matching credential-dumping patterns, mapped to Sysmon Event ID 10):
Import-Module Invoke-AtomicRedTeam
Invoke-AtomicTest T1003.001 -TestNumbers 1
# Blue team checks: did EDR alert on procdump64.exe accessing lsass.exe?
# Did the Sysmon ProcessAccess (Event ID 10) rule fire on
# TargetImage == lsass.exe with a suspicious GrantedAccess mask?
Walkthrough / Exploitation
A typical exercise session follows a repeatable structure:
1. Scoping call: agree on ATT&CK techniques in scope, target systems,
and the real-time communication channel (shared call/chat).
2. Red executes technique #1; blue watches the console live and
reports what fired within an agreed observation window.
3. Score the result: Detected / Detected-late / Not detected, with the
specific alert or log evidence attached.
4. If missed, blue drafts or tunes a detection (Sigma rule, EDR custom
rule) on the spot; red reruns the technique to validate the fix.
5. Repeat for each technique; update the ATT&CK Navigator layer.
6. Joint debrief: prioritized list of detection gaps, false-positive
risk of new rules, and follow-up owners.
The retest step in item 4 is what distinguishes a purple team result from a paper recommendation: a gap is not considered closed until the same technique, rerun, actually produces an alert.
Note: Purple teaming is not a replacement for blind red team or penetration testing — it validates detection engineering for known techniques, but a collaborative exercise cannot measure whether the SOC would notice and respond to a novel attack chain under real adversarial pressure, which is what an unannounced exercise tests.
Opsec: Some atomic tests are inherently disruptive (service stops, scheduled-task creation, registry run-key persistence) — always review and, where provided, execute the framework’s
cleanup_commandafter each test, and avoid running destructive atomics (e.g. simulated ransomware file encryption) outside an isolated lab.
Detection and Defense
- Maintain an ATT&CK Navigator coverage layer as a living artifact, updated after every exercise, to track detection maturity over time rather than as a one-off report.
- Feed gaps directly into a detection engineering backlog with owners and target dates, not just a findings list that goes stale.
- Regression-test detections in CI where possible — rerun key atomics on a schedule to catch a rule silently breaking after a SIEM/EDR upgrade.
- Prioritize by threat relevance, using intelligence about techniques actually used against the organization’s sector rather than testing the full ATT&CK matrix indiscriminately.
- Tune, don’t just alert — a detection that fires but drowns in false positives is not meaningfully better than no detection.
Real-World Impact
Purple teaming has become a standard complement to, rather than a replacement for, threat-intelligence-based red teaming programs such as the financial sector’s TIBER-EU and CBEST frameworks, precisely because those programs are expensive, infrequent, and blind by design — they measure whether detection works but do not efficiently fix it. Organizations running regular purple team cycles typically see measurable reduction in mean time to detect for common ATT&CK techniques, since gaps are closed within the exercise rather than waiting for the next full engagement to resurface them.
Conclusion
Purple teaming trades the realism of a blind engagement for speed and coverage: by removing the surprise element and putting red and blue in the same room, technique-level detection gaps get found, fixed, and retested in hours instead of months. It is most effective as a recurring practice mapped to real threat intelligence, feeding a living ATT&CK coverage map rather than a one-time compliance checkbox.
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