Welcome to the Deciphering File Formats MCQs Page

Dive deep into the fascinating world of Deciphering File Formats with our comprehensive set of Multiple-Choice Questions (MCQs). This page is dedicated to exploring the fundamental concepts and intricacies of Deciphering File Formats, a crucial aspect of Reverse Engineering. In this section, you will encounter a diverse range of MCQs that cover various aspects of Deciphering File Formats, from the basic principles to advanced topics. Each question is thoughtfully crafted to challenge your knowledge and deepen your understanding of this critical subcategory within Reverse Engineering.

Check out the MCQs below to embark on an enriching journey through Deciphering File Formats. Test your knowledge, expand your horizons, and solidify your grasp on this vital area of Reverse Engineering.

Note: Each MCQ comes with multiple answer choices. Select the most appropriate option and test your understanding of Deciphering File Formats. You can click on an option to test your knowledge before viewing the solution for a MCQ. Happy learning!

Deciphering File Formats MCQs | Page 4 of 9

Explore more Topics under Reverse Engineering

01

Introduction to Reverse Engineering

02

Low Level Software 🔒

03

Windows Fundamentals 🔒

04

Reversing Tools 🔒

05

Beyond the Documentation

06

Auditing Program Binaries 🔒

07

Reversing Malware 🔒

08

Piracy and Copy Protection

09

Antireversing Techniques 🔒

10

Breaking Protections 🔒

11

Reversing .NET 🔒

12

Decompilation

13

Deciphering Code Structures 🔒

14

Understanding Compiled Arithmetic

15

Deciphering Program Data 🔒

Q31.

Why is it important to establish which system (and other) services the program utilizes in Cryptex?

In order to track Cryptex’s I/O accesses

In order to decrypt the .crx file format

In order to get an overview of how Cryptex works

In order to observe the encrypted data

Discuss

Answer: (a).In order to track Cryptex’s I/O accesses Explanation:Establishing which system (and other) services the program utilizes is critical because in order to track Cryptex’s I/O accesses (which is what you’re going to have to do in order to find the logic that generates and deciphers .crx files) you’re going to have to place breakpoints on these function calls.

Q32.

Why is it difficult to decipher a file format by merely observing the data?

The file format is encrypted

The file format does not contain any recognizable patterns

The file format intentionally hides its contents

All of the above

Discuss

Answer: (b).The file format does not contain any recognizable patterns Explanation:Even with programs that don’t intentionally hide the contents of their file formats, it is often very difficult to decipher a file format by merely observing the data.

Q33.

What does the import list reveal about Cryptex.exe?

It uses direct calls into Win32 File I/O APIs.

It uses the Windows Crypto API.

It statically links with other libraries.

All of the above.

Discuss

Answer: (d).All of the above. Explanation:The import list reveals that Cryptex.exe uses direct calls into Win32 File I/O APIs and the Windows Crypto API, as well as the fact that it may statically link with other libraries.

Q34.

What is the Windows Crypto API?

A library for debugging software.

A cryptographic library that provides support for CSPs.

A generic programming interface for Windows.

An algorithm for decrypting data.

Discuss

Answer: (b).A cryptographic library that provides support for CSPs. Explanation:The Windows Crypto API is a cryptographic library that provides support for installable cryptographic service providers (CSPs) and can be used for encrypting and decrypting data using a variety of cryptographic algorithms.

Q35.

What is the benefit of Cryptex using the Windows Crypto API?

It makes it easier to determine which encryption algorithms the program employs.

It makes it harder to determine which encryption algorithms the program employs.

It allows Cryptex to encrypt files without a key.

It allows Cryptex to bypass Windows security protocols.

Discuss

Answer: (a).It makes it easier to determine which encryption algorithms the program employs. Explanation:The fact that Cryptex uses the Crypto API can be seen as good news because it means that it is going to be quite trivial to determine which encryption algorithms the program employs and how it produces the encryption keys.

Q36.

What is the purpose of obtaining a list of imported functions?

To determine which system services the program utilizes.

To track the program's I/O accesses.

To get an overview of the program and how it works.

All of the above.

Discuss

Answer: (d).All of the above. Explanation:Obtaining a list of imported functions can provide an overview of how the program works, establish which system services the program utilizes, and help track the program's I/O accesses.

Q37.

What is the easiest way to check Cryptex's password verification process?

Create an archive

Start Cryptex in a debugger

Type in the correct password

Trace back from printf call

Discuss

Answer: (b).Start Cryptex in a debugger Explanation:The easiest way to go about checking Cryptex's password verification process is to start Cryptex in a debugger, feeding it with an incorrect password, and catch the place in the code where Cryptex notifies the user that a bad password has been supplied.

Q38.

Which runtime library function does Cryptex use for printing messages to the console window?

CryptEncrypt

CreateFile

ReadFile

printf

Discuss

Answer: (d).printf Explanation:Cryptex uses the printf function from MSVCR71.DLL runtime library for printing messages to the console window.

Q39.

What does the presence of the printf function in the runtime library list tell you?

It tells you how Cryptex stores the passwords

It tells you how Cryptex encrypts and decrypts data

It tells you how Cryptex catches moments where it prints certain messages to the console window

It tells you how Cryptex links with other libraries

Discuss

Answer: (c).It tells you how Cryptex catches moments where it prints certain messages to the console window Explanation:The presence of the printf function in the runtime library list tells you that it is used for printing messages to the console window and you can catch moments where Cryptex prints certain messages to the console window.

Q40.

Which DLL module reveals that Cryptex apparently uses direct calls into Win32 File I/O APIs such as CreateFile, ReadFile, WriteFile, etc.?

KERNEL32.dll

MSVCR71.DLL

ADVAPI32.dll

None of the above

Discuss

Answer: (a).KERNEL32.dll Explanation:The entries in KERNEL32.dll are highly informative because they're telling us that Cryptex apparently uses direct calls into Win32 File I/O APIs such as CreateFile, ReadFile, WriteFile, etc.

Page 4 of 9

Low Level Software 🔒

Windows Fundamentals 🔒

Reversing Tools 🔒

Auditing Program Binaries 🔒

Reversing Malware 🔒

Antireversing Techniques 🔒

Breaking Protections 🔒

Reversing .NET 🔒

Deciphering Code Structures 🔒

Deciphering Program Data 🔒

Welcome to the Deciphering File Formats MCQs Page

Deciphering File Formats MCQs | Page 4 of 9

Explore more Topics under Reverse Engineering

Introduction to Reverse Engineering

Beyond the Documentation

Piracy and Copy Protection

Decompilation

Understanding Compiled Arithmetic

Suggested Topics

UNIX

Java Programming

Data Structures and Algorithms

Software Architecture and Design

Internet of Things (IoT)

SQL Server

Neural Networks

CompTIA PenTest+ Certification Exam PT0 002

Computer Hardware