This is a xanity leak for those interested in malware research.
It keeps the stub updated and FUD and with its built-in Scanner, that does not distribute, it will be FUD almost for a while. Xanity uses CodeDom to compile the Stub to a very low Size(49kb). This program was written in VB (.Net Framework required) and uses PHP to communicate with the servers, so this works without opening any port.
The setup tutorial can be found here: https://www.youtube.com/watch?v=WUTzpeevEC4