Trainers · Facilitation guide
Facilitating the brute-force lab
A complete lesson plan for the flagship lab — T1110 · Brute Force. Pre-brief, hands-on, and debrief, timed for a single class. Bring this page to the session and run it top to bottom.
This assumes your cohort is already provisioned and students can sign in. If not, run Running a cohort first.
Learning objectives
By the end of the lab, a student can:
- Recognise an SSH brute-force attack from authentication telemetry.
- Identify the four evidence dimensions of any alert: what, from where, how much, how fast.
- Commit to a disposition and justify it with specific, cited evidence.
- Compare their own verdict against an independent AI analyst and articulate why they agree or disagree.
Timing block (45–60 minutes)
| Segment | Time | What happens |
|---|---|---|
| Pre-brief | ~10 min | Set the scene, hand out the four-questions framework, do not give away the answer. |
| Hands-on | ~25–35 min | Students start the lab, investigate, and submit a disposition. You watch the progress table. |
| Debrief | ~10–15 min | Walk the student-vs-AI comparison, surface reasoning, draw out the lesson. |
The pre-brief — what to say
Keep it short and don't spoil the verdict. Something like:
"In a moment you'll start a lab. Real activity will be generated in your own sandbox, a detection will fire an incident within about a minute, and your job is to figure out what's going on and call it. You'll submit a disposition — true positive, false positive, benign, or duplicate — and a short rationale. Before you decide anything, answer four questions about the evidence: what happened, from where, how much, and how fast. Don't rush to a verdict; let the evidence get you there."
That's enough. Resist the urge to describe the attack — discovering it is the exercise.
The four-questions framework to coach
As you move around the room, steer students back to these four questions rather than handing them conclusions:
- What happened? Repeated failed authentications — for which account?
- From where? How many source IPs? Is it one or many?
- How much? How many attempts, and how does that compare to the detection threshold?
- How fast? Over what window? Is this a human pace or a machine pace?
When a student can answer all four, the verdict tends to fall out on its own.
If a student is stuck, ask a question, don't give an answer: "Could one person have logged in that many times that quickly?" lands far better than "it's a brute-force attack."
Common mistakes to watch for
- Calling it a false positive. Some students assume any noisy alert is the detection over-firing. Push them to the evidence: the volume and speed are real and abnormal.
- Thin rationale. A correct disposition with a one-line "it's a brute force" loses the rationale points. Coach them to cite the specifics — the account, the source IP, the count, the window.
- Ignoring the timing signal. Students often fixate on the failure count and miss that the speed is what proves it's automated. The 5-minute window is the tell.
Discussion questions
- Why are speed and volume a signal at all? What would normal failed logins look like?
- What single change would turn this into a false positive or benign event? (e.g. the same volume from an internal scanner, or a known automation account.)
- The detection threshold here is 20 attempts. What are the costs of setting it too low? Too high?
The debrief — built on AI vs human
Open the Cohort progress table and sort for the student-vs-AI disagreements. Those rows are your lesson:
- Pick a row where a student's disposition differs from the AI analyst's verdict. Open the incident with the class.
- Ask the student to defend their call out loud using the four questions. Then read the AI's verdict and confidence.
- Resolve it against ground truth — this is a true positive — and draw the lesson: confidence is not correctness; evidence decides.
- Close with a row where student and AI agreed and both were right, to show what a clean, well-justified call looks like.
For the student-facing version of this investigation, share the walkthrough. It mirrors the same four-questions method.
Run this once and you'll have your own rhythm. Next: Reading results for deeper progress-table reading, or Running a cohort to set up the next class.