Get the list of admin pages system path

$default_pages = array(
    'admin*',
    'files*',
    'system/ajax*',
    'media/browser*',
    '*/edit',
    '*/autocomplete*',
    'node/add*',
    'batch',
    'user',
    'user/*'
  );

For a full list of admin paths, check Verify, Define and Get Drupal admin paths post