Privilege Escalation Assessment

Description: Investigating privilege escalation incidents forensically on workstations and server systems is critical in identifying how an attacker or malicious user gained elevated access. Privilege escalation can occur in various ways, such as exploiting system vulnerabilities, misconfigurations, or leveraging stolen credentials.

1. Understanding Privilege Escalation

• Vertical Escalation: The attacker gains higher-level privileges (e.g., regular user to the administrator).

• Horizontal Escalation: The attacker expands access across accounts at the same privilege level.

• Common Techniques: Exploiting vulnerabilities, password cracking, manipulating user accounts, token manipulation, etc.

2. Data Collection and Preservation

• Forensic Imaging: Create forensic images of affected systems using tools like FTK Imager or dd.

• Memory Capture: Use tools like WinPmem or Magnet RAM Capture to capture live memory.

• Log Collection: Collect relevant logs, including security logs, system logs, application logs, and audit logs.

3. Initial Analysis and Identification

• Security Logs Analysis: Look for anomalous login activities, especially Event IDs 4624 (successful login), 4625 (failed login), and 4672 (special privileges assigned).

• Account Review: Examine user accounts for unauthorised creation, modification, or elevation of privileges.

• System and Application Logs: Check for logs indicating changes in system settings or application configurations that could lead to privilege escalation.

4. In-Depth Investigation

• Vulnerability Exploitation: Identify if any known vulnerabilities have been exploited for privilege escalation. Tools like Nessus or OpenVAS can help retrospectively identify vulnerabilities.

• Group Policy Analysis: Review group policies for misconfigurations that may have allowed privilege escalation.

• File and Registry Analysis: Look for unauthorised modifications in critical system files and registry entries that could indicate privilege changes.

5. Artifact Analysis

• Windows Registry: Investigate keys related to user accounts and privileges.

• Event Tracing Logs: Examine ETL files for evidence of privilege escalation activities.

• Scheduled Tasks: Check for any scheduled tasks created or modified by unauthorised users.

• Service Configuration: Analyse services to see if any have been modified to run with higher privileges.

6. Network Analysis (if applicable)

• Analyse network traffic for signs of lateral movement or external communications related to the privilege escalation.

7. Use of Specialised Forensic Tools

• Forensic Suites: Tools like EnCase, X-Ways Forensics, or Autopsy for comprehensive analysis.

• Windows-specific Tools: Windows Event Viewer, Sysinternals Suite, AccessChk, and Process Monitor.

8. Documentation and Reporting

• Detailed Documentation: Document every step, including tools used, findings, and methodologies.

• Forensic Report: Prepare a comprehensive report detailing the privilege escalation incident and its impact.

9. Post-Investigation Actions

• Remediation and Mitigation: Implement necessary fixes, security updates, and policy changes.

• Recovery: Restore systems and data from backups if necessary.

• Lessons Learned: Conduct a review to improve security posture and response strategies.

10. 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.

11. Key Considerations

• Legal and Compliance: Ensure all investigative actions comply with legal and organisational guidelines.

• Chain of Custody: Maintain a clear chain of custody for all forensic evidence.

• Confidentiality and Integrity: Handle all data securely and maintain its integrity.

Each privilege escalation incident is unique and might require a customised approach. Tailor the investigation to the specifics of the case and the environment in which you are operating.