Dynamic Analysis Walkthrough: Tools and Techniques for Malware Behavior Analysis

Dynamic analysis is a critical process in malware analysis, allowing cybersecurity professionals to observe how malicious software behaves in a controlled environment. This walkthrough provides an overview of essential tools and techniques used in dynamic analysis to examine malware behavior effectively.

What Is Dynamic Analysis?

Dynamic analysis involves running malware in a controlled environment to analyze its behavior. Unlike static analysis, which focuses on dissecting the code without execution, dynamic analysis executes the malware to observe its runtime characteristics, such as network communications, file changes, and registry modifications.

To perform dynamic analysis safely, tools like Windows Virtual Machines (VMs) and REMnux are used. These platforms create isolated environments to prevent the malware from affecting other systems.

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Dynamic Analysis Tools

1. T Studio

T Studio is a versatile tool useful for both static and dynamic analysis. By loading a malware sample, such as WannaCry, T Studio provides detailed information, including:

• File properties (e.g., 32-bit GUI executable).
• Hash values (SHA-256), which can be cross-checked on platforms like VirusTotal to determine detection rates among various vendors.
• Indicators of compromise (IOCs), such as suspicious libraries, APIs, and embedded strings.
• Classification of suspicious activities into three levels, helping prioritize investigations.
• Details of imported libraries and flagged DLLs, enhancing insight into malware capabilities.

2. Process Hacker

Process Hacker is an advanced process management tool that monitors system processes in real time. Its features include:

• Listing all running processes and their associated details, such as file paths and start times.
• The ability to terminate or manipulate processes, unlike standard task managers.
• Providing information about threads, handles, and loaded modules, making it indispensable for dynamic analysis.

3. Regshot

Regshot captures snapshots of the Windows registry before and after running a malware sample. By comparing these snapshots, analysts can:

• Identify modified, added, or deleted registry keys.
• Generate detailed reports highlighting changes, providing insight into malware persistence mechanisms.

4. Process Monitor (ProcMon)

ProcMon tracks system events, such as file creation, registry access, and network activity. Key features include:

• Real-time monitoring of processes initiated by malware.
• Exporting logs for further analysis in tools like ProcDOT, which visualizes process interactions and dependencies.

5. ProcDOT

ProcDOT works in conjunction with ProcMon, generating a graphical representation of process activity. This visualization aids in:

• Understanding how malware interacts with system processes.
• Identifying malicious behavior chains efficiently.

6. x64 Debugger

x64 Debugger is used for debugging 32-bit and 64-bit malware samples in a sandboxed environment. Analysts can:

• Set breakpoints to halt code execution at specific points.
• Step through instructions and examine the stack, symbols, and function breakdowns.
• Gain a deeper understanding of the malware’s runtime behavior.

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Networking Tools on REMnux

1. Wireshark

Wireshark captures and analyzes network traffic to understand how malware communicates with external servers. Key uses include:

• Monitoring outbound traffic from the malware-infected VM.
• Filtering by IP address to isolate communications.
• Identifying attempts to exfiltrate data or contact command-and-control (C2) servers.

2. Fake DNS and IP Tables

These tools help simulate adversary-controlled servers and monitor malware’s communication attempts. By redirecting traffic to a controlled environment, analysts can capture and study network packets for clues about the malware’s intentions.

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Best Practices for Dynamic Analysis

1. Isolated Environment: Always use a sandboxed VM or a dedicated lab network to prevent malware from spreading.
2. Baseline Snapshots: Take system and registry snapshots before executing the malware for accurate comparison.
3. Monitor Continuously: Use tools like Process Hacker and ProcMon to observe runtime changes.
4. Use Visualization: Tools like ProcDOT simplify complex data and highlight key relationships between processes.

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Conclusion

Dynamic analysis is an essential skill for malware analysts, enabling them to understand the real-world behavior of threats. By leveraging tools like T Studio, Process Hacker, Regshot, ProcMon, and networking utilities on REMnux, cybersecurity professionals can detect, analyze, and mitigate malicious activity effectively.