Definition: The word "index.php.bak" refers to a file containing a PHP script that has been compiled, executed on the server's hard drive (i.e., kernel), and is then saved as an archive with a .bak extension in the same directory. The term "index.php.bak" signifies the "index.php" file which contains a compiled and executed PHP script. The contents of this file are encrypted and compressed for security reasons, making it inaccessible on local devices without special decryption keys.
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