Initial Access Assessment

Description: Investigating initial access in a network, particularly in Windows workstations and server systems, involves a structured approach to identify how an unauthorised entity first gained entry. This process is critical for understanding the scope and impact of a security incident.

1. Initial Preparation and Response

• Initial Assessment: Confirm the breach and assess the scope.

• Secure Your Environment: Ensure the investigation is conducted securely to prevent further compromise.

• Containment: Isolate affected systems to prevent lateral movement or further damage.

• Preserve Evidence: Immediately secure and preserve logs and data that could be critical for the investigation.

2. Identify Entry Points

• Review Logs: Check security logs, system logs, application logs, and firewall logs for unusual activities.

• Analyse Network Traffic: Look for anomalies in network traffic that could indicate unauthorised access.

• Examine Entry Points: Common entry points include email (phishing), remote desktop protocol (RDP), web applications, and external devices.

3. System-Specific Investigations

• Windows Workstation:

• Check Event Viewer for login attempts, application errors, and system messages.

• Analyse the Windows Security Logs for failed login attempts or unusual successful logins.

• Use tools like Process Explorer to examine running processes for signs of malicious activity.

• Windows Server:

• Examine IIS logs if the server hosts web applications.

• Review Active Directory logs for unauthorised changes.

• Check database logs to see if the server hosts critical databases.

4. Forensic Analysis

• Disk and Memory Forensics: Use tools like Volatility for memory analysis and Autopsy for disk forensics.

• Timeline Analysis: Build a timeline of events to understand the sequence of actions taken by the attacker.

• Artifact Analysis: Examine files, registry entries, and other system artefacts for signs of tampering or unauthorised access.

5. Malware Analysis (If Applicable)

• Identify Malware: Use antivirus scans and malware analysis tools to identify and analyse malicious software.

• Reverse Engineering: If skilled resources are available, reverse-engineering malware can provide insights into its capabilities and origin.

6. Utilise Threat Intelligence

• Cross-reference Indicators of Compromise (IoCs): Compare findings with known IoCs from threat intelligence sources.

• Contextualise the Attack: Understand if the attack is part of a more extensive campaign or linked to known threat actors.

7. Interviews and Internal Investigation

• Conduct Interviews: Talk to users who might have witnessed unusual activities or received phishing emails.

• Review Internal Policies: Check if any recent changes in network or security policies could have opened up vulnerabilities.

8. Documentation and Reporting

• Detail Findings: Document every step taken and evidence found during the investigation.

• Report to Stakeholders: Provide clear and comprehensive reports to relevant stakeholders, including technical details and business impact.

9. Post-Investigation Actions

• Remediation: Address the identified vulnerabilities and entry points.

• Monitoring: Enhance monitoring capabilities to detect similar attempts in the future.

• Lessons Learned: Conduct a post-mortem to improve security posture and response capabilities.

10. Legal and Compliance Considerations

• Legal Compliance: Ensure the investigation complies with legal requirements and industry standards.

• Data Protection: When handling sensitive information, consider privacy and data protection laws.

11. Tools and Techniques

• Digital Forensics:

  • Specialised tools for evidence collection and analysis:

    • OpenText EnCase Forensics (commercial tool)

    • FTK (Forensic Toolkit)

    • Volatility (memory forensics)

    • Autopsy (open-source)

    • Cyber Triage (commercial tool)

    • Binalyze AIR (commercial tool)

    • Belkasoft (commercial tool)

    • Oxygen Forensics (commercial tool)

    • X-ways Forensics (commercial tool)

    • The Sleuth Kit (open-source tool)

    • Eric Zimmerman Tools (open-source tool)

  • Techniques include timeline analysis, file recovery, and reverse engineering.

• Incident Response:

  • Tools for monitoring, containment, and eradication:

    • SIEM (Splunk, QRadar, Microsoft Sentinel, Sumo Logic, Graylog, Elastic Security, LogRhythm, Datadog, Exabeam)

    • EDR (CrowdStrike, SentinelOne, Defender for Endpoint, Cortex XDR, FortiEDR)

    • Firewalls and IDS/IPS systems

  • Techniques include log analysis, threat containment, and system restoration.

12. Conclusion

Forensic investigation of initial access is a meticulous and detailed process. Each step is critical to uncovering the full scope of the intrusion and preventing future incidents. Stay updated with the latest forensic techniques and tools as cyber threats evolve.