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Brixton Foods: the directory answered a request it should have refused operation cover
IntermediateSIEMXDRPRO

Brixton Foods: the directory answered a request it should have refused

A food manufacturer's help desk raised a ticket at lunchtime: an overnight production report had not written to the file share, and one workstation had been slow all morning. By the evening the share was unreadable and an administrator account nobody on the IT rota recognises had been busy on the domain controllers. You have the day's Windows Security feed and the endpoint telemetry for the estate. Reconstruct what the operator did between the first mailbox and the unreadable share, and name the accounts and hosts the response team has to act on.

50m
5 tasks
50 points
Pro

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Investigation Tasks

Complete each task by investigating alerts and submitting your findings.

1

Find the foothold

50

One workstation showed activity this morning that ran ahead of anything on the servers. Work the endpoint process records and identify the workstation where the intrusion began.

Hint available
2

Identify the controller that was replicated

55

The directory itself was asked to replicate during the intrusion. Determine which domain controller served that request.

Hint available
3

Attribute the replication request

55

The replication request you traced was made under a specific account. Read the account name off the directory object-access record so it can be disabled and its sessions revoked.

Hint available
4

Recover the credential-access precursor

60

Before the directory was touched, something on the foothold read credential material out of memory. Identify the tool that opened the credential process so its hash can be pushed to the rest of the fleet.

Hint available
5

Classify the directory-replication technique

55

Summarize for the incident report how the operator pulled domain credentials without cracking a single password. Map the core credential-theft step to its MITRE ATT&CK technique.

Hint available

5 tasks · 275 points total

Training Tools

Skills You'll Build

Investigate realistic security alerts
SIEM log analysis
XDR log analysis
MITRE ATT&CK® technique identification
Triage decisions: escalate, investigate, or close
Evidence collection and documentation
Job-ready incident response methodology
Intermediate

Requires foundational alert triage skills. Multiple data sources to correlate.

Prerequisites

  • Basic understanding of security alerts
  • Familiarity with SIEM concepts
  • Familiarity with XDR concepts

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