In the realm of penetration testing and red teaming, gaining access to user credentials is often the most direct path to escalating privileges and achieving objectives. Credential harvesting and dumping are techniques used to extract sensitive authentication information, such as usernames, passwords, password hashes, and session tokens, from systems and individuals. This knowledge is crucial for understanding how attackers operate and how to defend against them, a core competency for the SANS GIAC Security Expert (GSE) certification.

Credential harvesting involves actively seeking out and collecting authentication data. This can be achieved through various methods, ranging from passive reconnaissance to active exploitation. The goal is to obtain credentials that can be used to authenticate to systems, applications, or services, thereby bypassing traditional security controls.

Credential dumping refers to the process of extracting credentials that are already stored on a system, often in memory or on disk. This is typically performed after an attacker has gained a foothold on a target machine. The extracted credentials can then be used for lateral movement within the network.

A variety of tools and techniques are employed for credential harvesting and dumping. Proficiency with these tools is essential for both offensive and defensive security professionals.

Protecting against credential harvesting and dumping requires a multi-layered approach, combining technical controls with user education.

Key defensive measures include:

• Implement Multi-Factor Authentication (MFA): This adds a significant barrier, as even if credentials are stolen, an attacker still needs a second factor to gain access.
• Regularly Patch and Update Systems: Keep operating systems and applications updated to mitigate vulnerabilities that could be exploited for credential theft.
• Harden Systems: Disable unnecessary services, restrict administrative privileges, and implement security configurations to limit attack vectors.
• User Education and Awareness Training: Educate users about the dangers of phishing, social engineering, and the importance of strong password practices.
• Endpoint Detection and Response (EDR): Deploy EDR solutions to detect and respond to malicious activities, including attempts to dump credentials.
• Credential Guard (Windows): Utilize Windows Credential Guard to isolate sensitive credential material and protect it from theft.
• Principle of Least Privilege: Ensure users and services only have the necessary permissions to perform their functions, limiting the impact of a compromised account.

For the SANS GIAC Security Expert (GSE) certification, a deep understanding of credential harvesting and dumping is paramount. The GSE exam often tests candidates on their ability to identify, exploit, and defend against these techniques in complex scenarios. Demonstrating practical knowledge of tools like Mimikatz, understanding the underlying Windows security mechanisms, and articulating effective mitigation strategies are key to success.