Reverse Engineering challenge #44.

There is an utility which encrypts/decrypts files using a password. There is an encrypted text file, the password is unknown. The encrypted file is a text in the English language.

The utility uses a relatively strong cryptosystem, nevertheless, it was implemented with a serious blunder. With the mistake present, it is possible to decrypt the file with a little effort.

Try to find the mistake and decrypt the file.

Windows x86.

The text file: files/text_encrypted.

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