@jfcp - yes once the script starts it seems to open a shell for a remote user. But you can only get the script to start after modifying the config file (entering the download directory/fu as a post processing script directory).
Additionally, the rogue usenetserver that was created as well showed 11Mb of downloaded data, and was left disabled.
If I were to do this I would also remove my traces in the config file afterwards.
Come up with a useful post-processing script? Share it here!