[3.5]Thousands of info_from_mbz_.... files

My Moodledata\temp\backup folder has thousands of info_from_mbz_.... folders. It seems like every minute one seems to be created.

In backup_general_helper.class.php you'll find this:

          // Extract moodle_backup.xml.

 244         $tmpname = 'info_from_mbz_' . time() . '_' . random_string(4);

 245          $tmpdir = $CFG->tempdir . '/backup/' . $tmpname;

 246          $fp = get_file_packer('application/vnd.moodle.backup');

Shouldn't this be cleaned up at any time? As seen in this threat our automated backup procedure is running but only has a success rate of about 15%.

Ken Task suggested I should use Moosh earlier, but since this is no regular Moodle plugin I can't use it.