How can I Restore/Decrypt the Vault encrypted files || How to Show Vault Hidden files after forgetting Password

NQ Vault is a very secure and popular Android app that hides important files on your phone. However, a major flaw exists in that the NQ vault uses the Xor cipher encryption system. I just used to write this program.

Working:

NQ Vault uses Xor cipher to encrypt your files. And it's very easy to crack. NQ Vault picks up your file and performs the xor operation on its first 128 bytes with a single-byte key.

Then it renames your file, changes its extension to .bin, and moves your encrypted file to your phone's/SystemAndroid/data/ folder.

Requirements:

I've written this program on my Android phone, which is suitable and meant to be run on Android phones. If you're on PC, then I'll write it very soon. The procedure is the same on both.

Also, you should have some programming knowledge. (Just for editing files.)

Stuff you will need 

1. C Compiler (I used C4droid V7.00) Download

2. Hex editor (I used the Macro Hex Edit app on Playstore.) Download

3. Bitwise Calculator (available online and on Android also available.) Open 

4. Vault.c Download

5. All Files Signature Open

Procedure:

1. Create an empty folder. 

2. Copy Vault. c and your encrypted files there. 

3. Vault Encrypted files will be available on your phone in the folder /SystemAndroid/Data/

there will be some folder like "MTUwOTQ0Mg==" or whatever. Look inside. There will be folders like .image or .video; inside, you will see your encrypted files with the .bin extension.

4. Copy these files to your newly created folder.

5. Open the encrypted file with a hex editor.

Note the first bytes for magic numbers(first few starting bytes). 

//If you're trying to decrypt the .jpg file. Then you should know it starts with bytes FF D8 FF.//

6. For other files, check the file signature from the site. (Link mentioned above)

7. Calculate the xor_byte through Bitwise Calculator. (Link mentioned above)

It's open your encrypted file and notes the first bytes, like 9F B8 9F. Google xor calculator, there xor your file's first bytes with FF D8 FF. (For .jpg files only. Every file has its magic number. Google yourself.)

8. You may notice the result will be 60 60 60. So 60 is my xor_byte for decrypting the "Sample.bin" file. Note your xor_byte, which will be different.

9. Edit and run the code.

10. Open the file Vault. c in C4droid or any other compiler.

11. Edit the fields xor_byte, file_input and file_output according to your needs and run the code.

Procedure(short version):

1. Create an empty folder. Copy Vault. c and your encrypted files there.

2. Calculate the xor_byte for the encrypted file.

3. Edit the fields the xor_byte, file_input and file_output inside Vault.c file. Then run the program.

4. And always have a backup before doing anything.