Ransomware is a type of malware from cryptovirology that threatens to publish the victim's personal data or permanently block access to it unless a ransom is paid off.

In this project I have demonstrated how ransomware is used to encrypt user’s images from ‘Pictures’ folder and demands ransom to decrypt them.

The BlowfishPhotoEncryptor is a Java program designed to encrypt photos using the Blowfish encryption.

• It begins by specifying the secret key and encryption algorithm to be used.
• The program identifies the user's home directory using the "user.home" system property.
• It locates the "Pictures" folder within the user's home directory.
• After a wait of 5 secs the program encrypts all image files (with extensions .png, .jpg, .jpeg, .bmp, and .gif) found in the "Pictures" folder and its subdirectories. It recursively encrypts files in subdirectories.
• After encryption, the original image files are deleted.
• The program creates a folder named "DecryptedPhotos" on the user's desktop.
• It selects one encrypted photo from the "Pictures" folder and decrypts it.
• The decrypted photo is saved in the "DecryptedPhotos" folder with the ".enc" extension removed.
• A GUI window is displayed, showing a message to inform the user that the photos have been encrypted and they must pay ransom amount to decrypt all their photos. It also displays an image and plays a sound clip to attract the user's attention.

When the user tries to run the compiled Java file (BlowfishPhotoEncryptor.java) using: ‘Java BlowfishPhotoEncryptor’:-

after 5 sec the images in the pictures folder will be encrypted and the user will not be able to open them. The user will see the prompt of warning demanding ransom in exchange of decrypting images.