Incident Response

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Incident Response

Outlines a structured approach to Manage and Mitigate security incidents effectively

Goals:

1. Minimize Impact
2. Reduce response Time
3. Hasten (Fast) Recovery
   • Incident Detection & Classification
   • Evidence Preservation
   • Communication & Reporting
   • Lessons Learned

Incident response process

Incident: Act of violating an explicit or implied security policy

Seven (7) Phase Model

1. Preparation: Policies & Procedures are written. Getting ready for future incidents
2. Detection: If a security incident has occurred and assessing the potential incident severity. The incident is categorized and triaged
3. Analysis: The incident is thoroughly examined & evaluated. Understand the scope & impact of the incident, evaluate the nature & potential consequences.
4. Containment: Limit the scope and magnitude of the incident by securing the data and minimize the impact on business operations.
5. Eradication: Focused on removing the malicious activity from a given system or network.
6. Recovery: Focused on restoring the effective system and services to there normal secure state.
   • Restoring from known good backup
   • Installing security patches
   • Implementing configuration updates
7. Post-incident activity / Lessons Learned: Analysis the incident and the response to identify whether the procedures and systems that we had worked properly or anything else we can do better next time. Actions: 1. Root cause analysis: Identify the source of the incident and how to prevent it in future - Define/Scope the incident - Determine the casual relationships that led to the incident - Identify an effective solution - Implement & track the solutions 2. Lessons learned process: What went right, what went wrong & what can we do better next time. 3. After-action report: Formalized report that collects information about what happened. Should have the ‘Root cause analysis & Recommendation for improvements’

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Threat Hunting

Method for finding hidden threats not caught by regular security monitoring. This is the act of being proactive in your defense as opposed to being reactive like you are with incident response. We are looking for threats within our network instead of waiting for them to attack us.

1. Establish a Hypothesis: Predicting high-impact, likely events through threat modeling and which events have the highest likelihood if there where to occur.
   • Who might want to harm us ?
   • Who might want to break into our networks ?
   • How might they be able to do that ?
2. Profiling Threat Actors and Activities: Creating scenarios that shows how a perspective attacker might attempt an intrusion and what there objectives might be
   • What TTPs (Tactics, Techniques & Procedures) might they use ?
   • Who wants to harm us ?
   • Are they insider threat, a hacktivist, a criminal organization or a nation-state APT ?

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Root Cause Analysis

A systematic process to identify the initial source of the incident and how to prevent if from occurring again.

1. Define the scope of the incident
2. Determine the casual relationships
3. Identify an effective solution
4. Implement & track the solution

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Digital Forensic Procedures

It is a systematic process of investigating and analyzing digital devices and data to uncover evidence for legal purpose, often in the context of criminal investigations or legal disputes.

Phases:

1. Identification: Ensuring the safety of the scene by preventing and evidence contamination and determining the scope of the evidence to be collected.
2. Collection: Must have proper authorization before collecting the evidence.
   • Following the order of volatility: Sequence in which a data source should be collected and preserved based of there susceptibility to modification or loss
     1. Collect data from system’s memory
     2. Capture data from system state
     3. Collect data from storage devices
     4. Capture network traffic and logs
     5. Collect remotely stored or archived data
   • Preserving the chain of custody: This is documented and verifiable record that tracks the handling, transfer and preservation of digital evidence from the moment it’s collected until itis presented in a court of law
3. Analysis: Systematically scrutinizing the data to uncover relevant information, such as potential signs of criminal activities, hidden files, time stamps and user interactions
4. Reporting : Documenting the findings, processing and the methodologies used during a digital forensic investigation.

Legal Hold: Formal notification that instructs employees to preserve all potential relevant electronic data, documents and records.

• Preservation Methods:
  1. Making backup copies
  2. Isolating critical systems
  3. Implementing access controls

Electronic Discovery: Process of identifying, collecting and producing electronically stored information during potential legal proceedings.

Code of ethics

1. Avoiding Bias
2. Repeatable Actions
3. Preservation of Evidence

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Data collection procedures

Steps

1. CPU Registry & Cache Memory : First collect data from anything that is highly volatile.
2. System Memory (RAM) , Routing Tables, ARP Cache, Process Table, Temporary Swap files
3. Data on persistent mass storage (HDD/SDD/Flash Drive)
4. Remote Logging & Monitoring Data
5. Physical Configuration & Network Topology
6. Archival Media

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Case Study: MedSecure Hospital Incident Response

Introduction

MedSecure Hospital, a mid-sized healthcare institution handling sensitive patient records and critical operational systems, experienced a cyber incident that threatened patient care, data security, and regulatory compliance. In this case study, we examine how MedSecure Hospital applied a seven‐phase incident response model to quickly detect, analyze, contain, eradicate, and recover from a ransomware attack, followed by a thorough post‐incident review. The process not only minimized downtime but also strengthened the organization’s overall security posture.

Background

MedSecure Hospital had implemented a robust cybersecurity program with a dedicated Incident Response Team (IRT). The organization had established regular security awareness training, maintained updated digital forensic tools, and ran continuous network monitoring through a SIEM (Security Information and Event Management) platform. Despite these preparations, advanced threat actors managed to exploit an unpatched vulnerability in a legacy imaging system, launching a ransomware attack that began encrypting several departmental servers.

Incident Timeline

• Day 0: Preparation
  MedSecure Hospital’s IT security policies and protocols were reviewed quarterly, and regular training exercises were conducted. A detailed incident response plan was in place, which included defined roles, communication hierarchies, and established backup routines.

• Day 1: Detection
  An alert was triggered by the SIEM, indicating unusual network traffic and a spike in file-access operations on the imaging department’s server. An on-duty technician also noted that several workstations were sluggish and showing error messages.

• Day 1: Analysis
  The Incident Response Team immediately convened to analyze logs, verify alerts, and isolate affected endpoints. Forensic software was used to determine that ransomware had infiltrated and begun encrypting critical files. Incident categorization confirmed a high-severity breach with potential impacts on patient care and data privacy.

• Day 1: Containment
  The team isolated affected servers by segmenting the network and disabling external communications from compromised systems. Remote access to non-affected systems was temporarily curtailed to prevent lateral movement of the malware.

• Day 2: Eradication
  With containment in place, the team worked to remove the ransomware. The eradication process involved deploying patches to the legacy imaging system, removing malicious software from infected servers, and revoking compromised credentials.

• Day 3: Recovery
  The recovery phase began by restoring data from verified backups and reimaging the affected servers. Systems were incrementally reconnected to the network under strict monitoring, ensuring that no remnants of the attack persisted.

• Day 4 & Beyond: Post‐Incident Activity
  A comprehensive lessons learned meeting was held with all stakeholders. The review documented the incident timeline, response effectiveness, and communication efficacy. The hospital updated its patch management policies, improved training for staff regarding phishing and suspicious network behavior, and revised its incident response plan.

Phase-by-Phase Analysis

1. Preparation

• Actions Taken:

  • Established a dedicated Incident Response Team (IRT) with clear roles and responsibilities.
  • Regular training sessions and simulated exercises were conducted to ensure preparedness.
  • A comprehensive incident response plan was maintained and tested.
  • Deployment of SIEM, forensic tools, and network monitoring systems.
  • Scheduled backups were regularly verified and stored offsite.

• Outcome:
  The groundwork allowed the team to respond immediately once the ransomware attack was detected.

2. Detection

• Actions Taken:

  • Continuous monitoring systems (SIEM) detected anomalous behavior (high network traffic and unusual file-access spikes).
  • On-site technicians reported system performance issues.
  • Initial indicators pointed to ransomware activity.

• Outcome:
  Early detection minimized the window during which the attackers could compromise additional systems.

3. Analysis

• Actions Taken:

  • Incident logs and forensic data were collected and reviewed.
  • The IRT performed a threat analysis to determine the scope and impact.
  • The attack was classified as high severity given its potential to disrupt patient services.

• Outcome:
  A detailed understanding of the attack vector and affected systems enabled focused response actions.

4. Containment

• Actions Taken:

  • Affected systems were immediately isolated by disconnecting them from the main network.
  • Network segmentation was enforced to prevent the spread of the ransomware.
  • Communication channels were established to coordinate containment efforts.

• Outcome:
  The spread of the malware was halted, reducing potential collateral damage.

5. Eradication

• Actions Taken:

  • The root cause—a vulnerability in the legacy imaging system—was identified.
  • The vulnerability was patched, and compromised systems were scrubbed of ransomware.
  • Compromised credentials were revoked and replaced.

• Outcome:
  All malware traces were eliminated from the environment, and the vulnerability was secured.

6. Recovery

• Actions Taken:

  • Affected servers were restored from secure backups.
  • Systems underwent rigorous testing before reintegration.
  • Normal operations resumed gradually, with continuous security monitoring in place.

• Outcome:
  Business continuity was maintained with minimal downtime, and data integrity was restored.

7. Post-Incident Activity / Lessons Learned

• Actions Taken:

  • A “lessons learned” session was conducted to review the incident response process.
  • Detailed reports documented the event, response actions, and recovery process.
  • Security policies were updated to cover lessons learned, including improved patch management and enhanced staff training.
  • Communication protocols were refined for future incidents.

• Outcome:
  The incident response plan was enhanced based on real-world experience, strengthening overall cybersecurity resilience.

Report

Title:
MedSecure Hospital Cyber Incident Response: A NIST-Aligned Report

Author:
Zeroday Mindset, Incident Response Specialist

Date:
April 08, 2025

Executive Summary:
This report details the incident response at MedSecure Hospital following a ransomware attack. The process adhered to a seven-phase model—Preparation, Detection, Analysis, Containment, Eradication, Recovery, and Post-Incident Activity—and aligns with NIST’s guidelines detailed in NIST SP 800-61. The systematic approach enabled swift mitigation, minimized operational disruption, and enhanced future resiliency.

1. Introduction

MedSecure Hospital faced a critical cybersecurity incident that threatened sensitive patient data and operational capabilities. By following a structured incident response process, the hospital successfully contained the breach and restored normal operations.

2. Incident Response Phases vs. NIST Framework

Phase	Incident Response Action	NIST Correspondence
Preparation	Training, planning, tool and backup readiness	Preparation (Phase 1 of NIST SP 800-61)
Detection	Early warning via SIEM and technician reports	Detection and Analysis (Phase 2)
Analysis	Forensic analysis and incident triage	Detection and Analysis (Phase 2)
Containment	Network segmentation and system isolation	Containment (Part of Phase 3)
Eradication	Removing ransomware, patching vulnerabilities	Eradication (Part of Phase 3)
Recovery	System restoration from backups and gradual reintroduction	Recovery (Part of Phase 3)
Post-Incident Activity	Lessons learned meeting and plan updates	Post-Incident Activity (Phase 4)

3. Key Findings and Recommendations

• Effective Preparation:
  Regular testing and updated training ensure the team is well-practiced in handling attacks.

• Early Detection:
  Proactive monitoring is essential. Investment in SIEM tools and anomaly detection reduces the breach window.

• Rapid Containment and Eradication:
  Isolating affected systems immediately prevents lateral movement. Establish explicit containment protocols.

• Recovery and Continuous Improvement:
  Regular backup tests and a clear recovery plan reduce operational downtime. Lessons learned drive policy updates.

4. Conclusion

MedSecure Hospital’s disciplined adherence to a seven-phase incident response process—aligned with NIST guidelines—demonstrates the importance of having a robust, well-practiced incident response plan. By continuously refining their practices through post-incident evaluations, the hospital has not only recovered from the attack but strengthened its defense against future threats.

This case study created by ChatGPT

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