“Members of a former software cracking group have discovered that audio files created with one of its cracked programs are distributed with each copy of the Windows XP” … (Read Article)
The files are at
%windir%\Help\Tours\WindowsMediaPlayer\Audio\Wav directory of Windows XP. If these files are opened with a HEX editor (or any Text Editor for that matter) the code contains the signature “Deepz0ne”, who was a member of former cracking group “Radium”.
Via: Tom’s Hardware Guide