Soru

Zorluk: ZorIncident Response Process and Playbooks

An enterprise Incident Response Team (IRT) detects unauthorized DNS redirection caused by ARP cache poisoning on a critical core network segment. According to standard NIST SP 800-61 incident response frameworks, in what order should the incident response team execute the following operational response steps?

  1. 1Capture network packet traces and volatile memory from the impacted hosts to preserve evidence.
  2. 2Apply static ARP entries on the gateway router and isolate the rogue host's switch port.
  3. 3Remove malicious ARP spoofing scripts from the compromised host and flush compromised ARP caches across the subnet.
  4. 4Re-enable dynamic resolution service on verified switches and monitor network traffic for residual anomalies.
  5. 5Conduct a post-mortem review with stakeholders to update network access control (NAC) policies and IR playbooks.

Cevap

The correct sequence follows the standard NIST incident response lifecycle: 1) Preserve evidence during Detection and Analysis, 2) Isolate the attack source during Containment, 3) Purge malicious tools and flush caches during Eradication, 4) Restore operations with monitoring during Recovery, and 5) Perform a lessons-learned review during Post-Incident Activity.
The standard incident response process requires systematically moving through Detection and Analysis (capturing volatile evidence), Containment (blocking rogue switch ports and applying static ARP mappings), Eradication (clearing poisoned ARP tables and deleting malicious scripts), Recovery (restoring standard network behavior under monitoring), and Post-Incident Activity (updating playbooks and holding a lessons-learned meeting).

Adım Adım Çözüm

1
Detection & Analysis Evidence Preservation
Network packet captures and volatile RAM are safely preserved without disturbing system artifacts.
Forensic evidence preservation is critical before taking intrusive isolation actions that could alter volatile memory state.
2
Containment
The rogue device's switch port is disabled and static ARP mappings temporarily halt active man-in-the-middle redirection.
Immediate containment prevents further scope expansion and stops unauthorized traffic interception.
3
Eradication
Malicious ARP spoofing tools are removed from compromised systems, and poisoned ARP tables across subnet hosts are cleared.
Eradication eliminates the threat vector and removes corrupted state from the environment.
4
Recovery
Normal dynamic network services are restored while heightened traffic logging verifies system health.
Recovery safely returns infrastructure to operational status under close monitoring to detect any persistence.
5
Post-Incident Activity
A formal lessons learned report is drafted and Network Access Control (NAC) policies are updated.
Post-incident activities complete the lifecycle by enhancing organizational security posture against future attacks.

Anahtar Kavram

NIST SP 800-61 Incident Response Lifecycle Phases
Bu soruyu puanla