[malvinas2]

In case you're using Linux the following command creates a copy of all existing cdart.png-files, which are found in the given directory and its subdirectories and the copy will be renamed to discart.png (the original file will not be deleted):  
find /path/to/search -type f -name 'cdart.png' -exec bash -c 'cp "$0" "${0/cdart/discart}"' {} \;