Incident Response Playbook for Windows Malware Detection (Updated 2025)

This Windows Malware Detection Incident Response Playbook provides a structured approach to detect, contain, remediate, and recover from malware incidents on Windows systems. Modern updates include advanced tools for endpoint detection, real-time monitoring, and secure data collection.

1. Preparation

Objective: Establish a proactive security posture to ensure rapid detection and response to malware incidents.

Key Steps:

1. Deploy Endpoint Detection and Response (EDR) Solutions:

   • Ensure that EDR is installed on all endpoints and configured to operate in both detection and prevention modes.

   • Test EDR rules with known Indicators of Compromise (IOCs).

2. Implement Additional Security Tools:

   • Use security tools such as Sysmon, SmartScreen, and Windows Defender.

   • Apply hardened security baselines recommended by ANSSI and CIS.

3. System Documentation:

   • Maintain an inventory of usual services, open ports, and scheduled tasks on critical systems.

   • Document access rights to sensitive directories and files.

4. Prepare Forensic Tools:

   • Ensure forensic tools such as FastIR, KAPE, FTK Imager, and WinPmem are readily available.

   • Establish procedures for both volatile data capture and disk imaging.

5. Regular Training and Testing:

   • Conduct regular security awareness training, focusing on malware threats.

   • Simulate malware incidents to test the effectiveness of response playbooks.

6. Log Management and Synchronisation:

   • Enable detailed event logging on Windows systems (e.g., audit logs, PowerShell logs).

   • Synchronise system clocks with a secure Network Time Protocol (NTP) server.

2. Identification

Objective: Detect the malware infection, determine its scope, and involve appropriate stakeholders.

Signs of Infection:

• Antivirus, EDR, or IDS alerting on suspicious files or processes.

• Inability to update security software or run manual scans.

• Unusual system behaviour, such as:

  • High disk or CPU usage.

  • Frequent application crashes or unexpected reboots.

  • Pop-up windows appearing without user interaction.

  • Sudden degradation in network performance.

Steps:

1. Capture Volatile Data:

   • Use tools like FTK Imager or WinPmem to capture volatile memory (e.g., running processes, network connections).

   • Take a triage image using tools like FastIR or KAPE.

2. Analyse Memory:

   • Look for rogue processes, code injections, and network artifacts.

   • Use tools such as Volatility to identify anomalies in the captured memory.

3. Check Persistence Mechanisms:

   • Investigate common persistence methods, such as:

     • Scheduled tasks.

     • Auto-start registry keys.

     • DLL search order hijacking.

     • Service creation or replacement.

   • Use Microsoft Autoruns for a comprehensive overview of auto-start entries.

4. Review Event Logs:

   • Analyse logs related to:

     • Account logins and access events.

     • Scheduled tasks and service executions.

     • Remote desktop (RDP) and SMB activity.

5. Generate a Super-Timeline:

   • Use tools like Log2timeline to create a timeline of key events for deeper analysis.

3. Containment

Objective: Limit the impact of the malware by isolating affected systems and preventing further spread.

Steps:

1. Isolate the Affected System:

   • Use EDR to remotely quarantine the machine.

   • If necessary, disconnect the machine physically from the network to prevent lateral movement.

2. Backup Critical Data:

   • Create a secure backup of critical business data before applying containment measures.

3. Prevent Access to Malicious Content:

   • Block known malicious IP addresses, domains, and file paths.

   • Restrict file sharing and access to sensitive network shares.

4. Monitor Network Traffic:

   • Use network monitoring tools to detect additional signs of malware propagation.

4. Remediation

Objective: Remove the malware and secure the system against future attacks.

Steps:

1. Remove Malicious Components:

   • Identify and remove malware binaries, registry entries, and any associated scripts.

   • Use Antivirus, YARA rules, and EDR to verify removal.

2. Apply Security Patches:

   • Patch all vulnerable software, including operating systems and applications.

   • Disable or remove unused services to reduce the attack surface.

3. Reset Credentials:

   • Enforce password changes for all local and domain accounts that may have been compromised.

   • Rotate sensitive credentials, including API keys and service account passwords.

4. Reinforce Security Policies:

   • Apply stronger access controls and enforce multi-factor authentication (MFA) on critical systems.

5. Recovery

Objective: Restore the system to normal operations and verify that all threats have been eliminated.

Steps:

1. System Reinstallation:

   • If feasible, perform a clean reinstallation of the operating system.

   • Restore files from clean, trusted backups.

2. Validate System Integrity:

   • Run full antivirus and EDR scans to ensure no malicious artifacts remain.

   • Test critical applications and services to confirm normal operation.

3. User Communication:

   • Notify affected users and provide guidance on secure practices.

   • Implement additional security awareness training if user error contributed to the compromise.

6. Lessons Learned

Objective: Document the incident, identify areas for improvement, and refine response procedures.

Steps:

1. Incident Report:

   • Compile a detailed report covering:

     • Initial detection and timeline of events.

     • Actions taken during containment, remediation, and recovery.

     • Indicators of compromise and root cause analysis.

2. Post-Incident Review:

   • Conduct a review with all stakeholders to assess the effectiveness of the response.

   • Identify gaps in detection, communication, and incident handling.

3. Update Playbooks:

   • Integrate lessons learned into existing response playbooks.

   • Update detection rules, threat intelligence feeds, and response protocols.

4. Continuous Improvement:

   • Regularly test incident response capabilities through tabletop exercises and simulations.

   • Strengthen partnerships with external response teams, such as CERTs and managed security providers.

Conclusion

This Windows Malware Detection Playbook equips SOC teams with a comprehensive approach to handling malware incidents. Regular updates to tools, procedures, and training programs will ensure ongoing readiness and resilience against evolving malware threats.

For additional resources, including malware analysis tools, sample timelines, and reporting templates, please contact our security operations team.