What are the pros and cons of static and dynamic malware analysis tools?

1 Static malware analysis tools

Static malware analysis tools are those that examine the malware without executing it. They can reveal information such as the file format, the metadata, the code structure, the strings, the imports, the exports, and the resources of the malware. Static malware analysis tools can be divided into two categories: disassemblers and decompilers. Disassemblers translate the binary code of the malware into assembly language, which is more readable for human analysts. Decompilers go a step further and attempt to reconstruct the original source code of the malware in a high-level programming language, such as C or Java. Some examples of static malware analysis tools are IDA Pro, Ghidra, and Radare2.

The main advantage of static malware analysis tools is that they are fast, safe, and reliable. They can analyze a large number of malware samples in a short time, without risking the infection of the analyst's system or the activation of the malware's defenses. They can also provide a consistent and accurate representation of the malware's code, regardless of its execution environment or configuration. However, static malware analysis tools also have some limitations. They cannot reveal the runtime behavior of the malware, such as its network communication, file manipulation, registry modification, or process injection. They may also fail to handle obfuscated or encrypted code, which can hide or change the malware's functionality.

2 Dynamic malware analysis tools

Dynamic malware analysis tools are those that execute the malware in a controlled environment and monitor its actions. They can capture information such as the system calls, the network traffic, the file system changes, the registry changes, and the memory dumps of the malware. Dynamic malware analysis tools can be divided into two categories: emulators and sandboxes. Emulators simulate the hardware and software components of a target system, such as the CPU, the memory, the operating system, and the applications. Sandboxes isolate the malware from the rest of the system, using techniques such as virtualization, containerization, or application-level isolation. Some examples of dynamic malware analysis tools are QEMU, Cuckoo Sandbox, and Sysinternals Suite.

The main advantage of dynamic malware analysis tools is that they can reveal the actual behavior of the malware, which may differ from its code analysis. They can also handle obfuscated or encrypted code, which may be decrypted or deobfuscated at runtime. They can also provide a more realistic and interactive analysis environment, where the analyst can modify the inputs, outputs, and parameters of the malware. However, dynamic malware analysis tools also have some drawbacks. They are slower, riskier, and less reliable than static malware analysis tools. They can take a long time to execute the malware, expose the analyst's system to potential infection or damage, and trigger the malware's anti-analysis or anti-debugging mechanisms. They may also produce different results depending on the execution environment or configuration of the malware.

3 Combining static and dynamic malware analysis tools

Static and dynamic malware analysis tools are not mutually exclusive, but rather complementary. They can provide different perspectives and insights on the same malware sample, and help the analyst overcome the limitations of each type. For example, static malware analysis tools can help identify the entry points, the functions, and the variables of the malware, which can then be used to set breakpoints, hooks, or patches in dynamic malware analysis tools. Dynamic malware analysis tools can help confirm or refute the hypotheses generated by static malware analysis tools, and provide additional information on the malware's behavior and impact. By combining static and dynamic malware analysis tools, the analyst can achieve a more comprehensive and effective malware analysis workflow.