Update README.md

Author: rickey-g

README.md

@@ -24,3 +24,6 @@ The code provides a communication channel for the attacker and infected client.
 - XAS_GATE = '/updates/'
 
 **The code is completely left as found on the original server, including the log files.**
+
+ESET has the complete source code of XAgent, read their report here:
+http://www.welivesecurity.com/wp-content/uploads/2016/10/eset-sednit-part-2.pdf