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Zorluk: Çok zorIncident Response Process and Playbooks

During a threat hunting exercise on an enterprise SCADA network, a SOC analyst identifies an unauthorized background service executing on a primary operational jump server. The rogue process is actively establishing covert encrypted DNS tunnels to external command-and-control (C2) servers to exfiltrate system telemetry. The incident response playbook mandates immediate threat containment while strictly maintaining volatile RAM evidence for subsequent forensics. Which of the following operational steps should the security team perform FIRST to adhere to the containment phase protocols?

  1. Apply a microsegmentation isolation policy at the managed switch port and firewall to sever outbound network connectivity while keeping the host powered on.Cevap
  2. B
    Execute an immediate forced reboot of the operational jump server to kill the rogue background service and clear compromised memory spaces.
  3. C
    Reimage the operational jump server using a baseline virtual machine snapshot from the secure deployment repository.
  4. D
    Deploy a detective intrusion detection rule in the SIEM to suppress future C2 alerts generated by the rogue background process during investigation.

Cevap

The operational team should isolate the jump server at the network level by applying microsegmentation firewall and switch port restrictions while preserving host power state for forensic acquisition.
Network-level microsegmentation isolates the compromised host from the network, immediately stopping data exfiltration and external command-and-control channels without interrupting power, thereby preserving volatile system RAM for forensic memory analysis.

Adım Adım Çözüm

1
Analyze the incident context and requirements.
Identified an active C2 covert DNS tunnel exfiltrating data on a critical server, with a requirement to contain threat activity without losing volatile RAM evidence.
Containment must balance stopping malicious traffic/exfiltration while upholding the order of volatility for digital forensics.
2
Evaluate containment actions against NIST/ISO incident response lifecycle phases.
Network-level isolation (microsegmentation) blocks outbound C2 traffic while preserving RAM.
Powering off or rebooting destroys volatile memory; reimaging belongs in recovery; alert suppression fails to contain the threat.
3
Select the correct immediate containment step.
Isolating the network connection while maintaining system uptime.
This directly fulfills containment objectives without destroying forensic artifacts.

Anahtar Kavram

Containment Strategy & Order of Volatility in Incident Response Playbooks
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