Understanding Meterpreter, the powerhouse tool for cybersecurity, is essential for any security enthusiast or professional. As an advanced, dynamically-extensible payload, it utilizes in-memory DLL injection stagers and is extended over the network at runtime. It operates entirely within the memory of the host computer and leaves no footprint, making it challenging for defenders to detect.

Meterpreter’s extensibility and flexibility sit at the heart of its functionality and effectiveness. Its modular structure allows security practitioners to extend its capabilities on the fly, using extensions written in Python, Java, PHP, and other common languages.

Basics of Meterpreter

Meterpreter is a Metasploit attack payload that is injected into a victim's system after a successful exploitation. Unlike other payloads that execute on the target and provide user interaction, Meterpreter sits in memory and conducts its operations transparently, making it more difficult for threat detection solutions to detect or block it.

Key Features of Meterpreter

Meterpreter comes with an extensive set of features that make it a widely used tool among penetration testers. WebSocket selection, transport controls, file system interaction, network interaction, system information gathering, privilege escalation, command execution, registry interaction, capturing keystrokes, and webcam control are just a few of its capabilities.

Understanding Meterpreter's Command Structure

Meterpreter commands are divided into 'Core' commands and 'Stdapi' commands. While Core commands manipulate the Meterpreter session itself, Stdapi commands provide interaction with the system the Meterpreter instance is running on. Understanding these commands is pivotal to grasping the usage and strategies involved in Meterpreter.

Advanced Usage Techniques

Aside from its basic functionality, Meterpreter can be used for advanced maneuvers such as pivoting, token manipulation, bypassing UAC, obtaining clear-text credentials, and more. Techniques such as 'Pass the Hash', 'Overpass the Hash', and 'Golden Ticket' give Meterpreter an edge over other payloads.

Meterpreter and Post-Exploitation

Meterpreter becomes a post-exploitation Swiss Army knife with the added capabilities of the post-exploitation sub-framework of Metasploit. It can help the attacker maintain persistence, evade detection, execute further attacks, scrape valuable information out of memory - anything that revolves around enhancing control over the compromised system or network.

Mitigation Techniques Against Meterpreter

As crucial as it is to understand Meterpreter's capabilities, it's equally essential to know the various mitigation techniques against it. Firewall configurations, regular patching, monitoring and logging, user awareness and training, along with whitelisting applications, are the first line of defense against Meterpreter-based attacks. More sophisticated techniques like threat hunting, behavior-based detection, and deception technology can also help secure systems effectively against sophisticated threats like Meterpreter.

In conclusion, Meterpreter stands as a testament to the complex and evolving landscape of cybersecurity, proving the need for exhaustive knowledge in defense and offence. Its advanced features, coupled with its stealthy operation, make it a cornerstone tool in any penetration tester’s arsenal. Understanding the intricacies of Meterpreter, therefore, is not optional; it’s a necessity in today’s threat landscape.