What's Your Malware Analysis Process? Quiz

A debugger lets the malware analyst step through the most interesting parts of the code, interacting with it and observing the effects of its instructions to understand its purpose. A breakpoint is a condition defined by the analyst that tells the debugger when it should pause the execution of the program, allowing the analyst to interact with the program with the help of the debugger's capabilities.

A malicious program usually wants to ensure that it continues to run on the system even after a reboot. There are numerous ways of accomplishing this, including adding an entry to the HKLM\Software\Microsoft\Windows\CurrentVersion\Run registry key that points to the specimen's file.

By using a "packing" utility, malware authors encode, encrypt or obfuscate the original executable, making it more difficult to analyze using static code analysis techniques. In such cases, the reverse-engineer typically has to unpack the program using a variety of approaches that might be challenging and time-consuming.

GetAsyncKeyState determines whether the specified key is pressed at the moment when this system call is made. One of the ways a keylogger can spy on the user's keyboard activities is to repeatedly iterate through all likely key values, checking whether each key is pressed.

Behavioral analysis examines the malware specimen's interactions with its environment: the file system, the registry (if on Windows), the network, as well as other processes and OS components. As the malware investigator notices interesting behavioral characteristics, he or she modifies the laboratory environment to evoke new characteristics. Code analysis reverse-engineers the malicious program to understand the code that implements the specimen's behavior. When looking at compiled programs, this process involves using a disassembler, a debugger and, perhaps, a decompiler to examine the program's low-level assembly or byte-code instructions.

The PE ("Portable Executable") header of a Windows executable stores critical information about the program that allows the Windows operating system to properly run the executable. One of the fields stores in the header is the Entry Point. This field stores the address of the instruction within the program that the operating system needs to execute first to begin running the program.

Malware analysts frequently patch the malicious program to modify how it executes, even though they typically don't have access to the program's original source code. For instance, the analyst might locate a defensive measure built into the specimen to confuse the analyst, and use patching to render that measure ineffective.

The x86 instruction set supports several general-purpose registers. EAX is one of them. Although general-purpose registers could be used by the program for any purpose, EAX is often used as the placeholder for storing the return value of a function.

Malicious code typically uses assembly instructions like JMP, RET, and CALL to perform jumps and alter the flow of execution. However, XOR is least likely to be used for this purpose. XOR is primarily used for bitwise operations and data manipulation, rather than controlling program flow. It is less commonly used for branching or jumping within a program, making it an unlikely choice for malicious code seeking to perform a jump.

Based on the options provided, the correct answer is D. Detecting the presence of a debugger. Malware is least likely to use this mechanism when defending itself against analysis. Detecting the presence of a debugger is a common defensive technique used by malware to evade detection and analysis. However, the other options listed (A. Inserting junk code instructions, B. Employing polarization techniques, and C. Making use of "tricky" jump instructions) are more commonly employed by malware to obfuscate its code and make analysis more difficult.