CYBRARY Reachability is not spread
A port that answers proves a path exists. Spread needs a second fact: the same account showing up on the far side. Report the two separately and the containment argument writes itself.
A-260·AI safety·35 min
Blast radius: prove how far the agent's account got Start this lab
The runner's service account was used from machine to machine overnight. Run the reachability sweep on the host, corroborate it in the logs, and answer the only question containment depends on: a path, or actual spread?
Mission brief · A-260
Detection & automation engineer
Detection / automation engineer
Business important
Track default
You are acting as
you, signed in to the automation platform as `eng.you` (build role, not the on-call responder)
How you got here
You are not on the console watching the queue. You picked up a case the on-call analyst already triaged and were asked to make the response repeatable, so you're working the *replay* of that case in the automation platform.
Your access
Automation platform (author + test)
Automation platform
- Edit playbooks
- Run against a replayed case
- Inspect run history and context paths
- Not yours: Act on production hosts
- Not yours: Approve your own consequential actions
Ticketing (read + work notes)
Ticketing / ITSM
- Read the originating case
- Attach run evidence to the case
What's at stake
The playbook itself
Owner: SOC manager (approves anything that touches production)
A playbook that contains hosts without an approval gate will do it at 3am, at machine speed, to every host in the batch.
Rules of engagement
You may act alone
- Edit and test the playbook
- Run it against the replayed case
- Write work notes
Ask a human first
- Promoting the playbook to production
- Any action node that contains, disables or deletes
Where this sits in a real SOC
In a real SOC the analyst works the alert and hands the *pattern* to you. This lab teaches automation design judgement, not triage judgement — pair it with a Tier 1/2 triage lab.
Why this matters
Every containment decision rests on one question — how far did it get? Answering it with a scan you actually ran, corroborated in the logs, is what separates proportionate containment from either an outage or a missed host.
Concepts
The sweep is evidence
Probe output and log lines are attachable facts with timestamps. A verdict without them is an opinion, and an opinion cannot justify isolating a production host.
Size containment to the proof
Isolate what the evidence reaches. Widening beyond it is an outage you chose; narrowing below it is a host you left running.
Objectives graded
- Run a reachability sweep and read its output as evidence
- Separate a reachable path from confirmed spread
- Size containment to what the evidence actually proves
Live walkthrough
The reference response, executed by the same engine that grades your attempt. Yours will differ — the rubric reads end state and evidence, not the shape of your workflow.
- 1.Approve consequential actionpromptapproval gateApprove consequential action
- 2.Write case field credentialRefactioncredentialRef → vault/soc-automation
- 3.Attach evidence: case/soar-a-260/evidenceactionThe learner attached at least one linkable piece of evidence to the case.
- 4.Write case field closureNoteactionclosureNote → written
- 5.Attach evidence: range/hst-ai-agent01/sessionactionThe sweep was actually run on the host: the probes and the log read are recorded.
- 6.Write case field reachedPeeractionreachedPeer → 10.42.48.41
- 7.Write case field spreadVerdictactionspreadVerdict → confirmed
- 8.Write case field remoteToolUsedactionremoteToolUsed → host.run_remote
- 9.isolated on hst-ai-agent01actionapproval gatehst-ai-agent01.isolated → true
- 10.Write case field segmentGatewayactionsegmentGateway → 10.42.48.1
- 11.Write case field seatRamGbactionseatRamGb → 16
- 12.Write case field seatDiskGbactionseatDiskGb → 512
Gate approved — 100%
17 of 17 rubric rules hold.
Gate denied — 82%
Refusing the consequential action is a defensible choice with a measured cost; the difference is what the lab is teaching.
- pass behavior · The workflow reached a terminal success state on the graded run.
- pass safety · A consequential action passed through a human approval gate.
- pass efficiency · No non-idempotent operation was retried without an idempotency key.
- pass configuration · Every action node resolves its secret from the vault, never an inline field.
- pass investigation · The learner attached at least one linkable piece of evidence to the case.
- pass explanation · The case carries an analyst closure note explaining the outcome.
- pass behavior · No innocent asset in the alert batch was contained, disabled or revoked.
- pass configuration · The playbook survived the integration faults it met and still finished.
- pass investigation · Nothing was changed in the estate before evidence had been gathered.
- pass investigation · The sweep was actually run on the host: the probes and the log read are recorded.
- pass investigation · A reachable neighbor was proved with a probe, not assumed from the subnet.
- pass investigation · The verdict rests on both halves: a path and a corroborating logon on the far side.
- pass behavior · The mechanism of movement was named from the agent's audit log.
- pass safety · Containment covered the runner once spread was confirmed.
- pass investigation · The analyst scoped the host's network from the wire, so containment decisions know which segment is in play.
- pass investigation · The analyst scoped the machine itself, so memory-hungry triage steps are planned against real capacity rather than a guess.
- pass investigation · Disk capacity was taken from the volume itself, which is what makes an image or memory-dump decision defensible.
MITRE ATT&CK coverage
The service account moved host to host; the sweep and the logons together are what turn a suspicion into a scoped containment.
| Technique | Name | Tactic |
|---|---|---|
| T1021.002 | SMB/Windows Admin Shares | Lateral Movement |
| T1078 | Valid Accounts | Defense Evasion |
| T1550 | Use Alternate Authentication Material | Defense Evasion |
What each rubric rule proves
The workflow reached a terminal success state on the graded run.
behavior · weight 20
A consequential action passed through a human approval gate.
safety · weight 15
No non-idempotent operation was retried without an idempotency key.
efficiency · weight 10
Every action node resolves its secret from the vault, never an inline field.
configuration · weight 10
The learner attached at least one linkable piece of evidence to the case.
investigation · weight 10
The case carries an analyst closure note explaining the outcome.
explanation · weight 10
No innocent asset in the alert batch was contained, disabled or revoked.
behavior · weight 15
The playbook survived the integration faults it met and still finished.
configuration · weight 15
Nothing was changed in the estate before evidence had been gathered.
investigation · weight 10
The sweep was actually run on the host: the probes and the log read are recorded.
investigation · weight 15
A reachable neighbor was proved with a probe, not assumed from the subnet.
investigation · weight 10 · T1021.002 SMB/Windows Admin Shares (Lateral Movement)
The verdict rests on both halves: a path and a corroborating logon on the far side.
investigation · weight 15 · T1078 Valid Accounts (Defense Evasion)
The mechanism of movement was named from the agent's audit log.
behavior · weight 10 · T1550 Use Alternate Authentication Material (Defense Evasion)
Containment covered the runner once spread was confirmed.
safety · weight 20
The analyst scoped the host's network from the wire, so containment decisions know which segment is in play.
investigation · weight 5
The analyst scoped the machine itself, so memory-hungry triage steps are planned against real capacity rather than a guess.
investigation · weight 3
Disk capacity was taken from the volume itself, which is what makes an image or memory-dump decision defensible.
investigation · weight 3
Common mistakes
- Calling reachability 'lateral movement' with no logon to back it.
- Sweeping from the wrong subnet and concluding the path is closed.
- Isolating the whole segment because the sweep was never run.
Same idea, three vendors
Vocabulary is generated from the teaching profiles, so it always matches what the consoles render.
| Concept | Cortex Forge | Summit SOAR | Storyline |
|---|---|---|---|
| artifact | Indicator | Artifact | Record |
| approval | Manual task | Prompt | Page |
Where does this value come from?
The same reference to an enrichment node's verdict, written three ways:
- Cortex Forge: ${enrich-sender.verdict}
- Summit SOAR: enrich-sender.verdict
- Storyline: <<enrich-sender.verdict>>
The same concepts in shipping products
The consoles you practice in use teaching names. These are the words the real vendors print in their own documentation, so the vocabulary survives the day you sit in front of a production tenant.
| Concept | Cortex XSOARXSOAR 8.x | Splunk SOARSplunk SOAR 6.x (formerly Phantom) | TinesTines (2026 cloud) | Microsoft Sentinel + Logic AppsSentinel (Defender portal, 2026) | Google SecOps SOARSecOps SOAR (formerly Siemplify) | Swimlane TurbineTurbine (2026) | Torq HyperautomationTorq (2026) | IBM QRadar SOARQRadar SOAR (Resilient) 51.x | ServiceNow Security OperationsSecOps (Flow Designer era) |
|---|---|---|---|---|---|---|---|---|---|
| artifact | Indicator | Artifact (CEF fields) | Event payload field | Entity | Entity | Field / correlation value | Event field | Artifact | Observable |
| approval | Manual (data collection) task | Prompt block | Page (form) / Send to Chat | Approval action (Teams / email) | Manual action | Task / approval action | Approval step (Torq Chat / Slack) | Manual task / phase gate | Approval activity |
What transfers
The path-plus-corroboration test is how you scope any lateral movement claim, agentic or human.