The client application communicates with the server application using TCP with encrypted UDP packets. This requires the user of the machine to either deliberately install this application or be tricked into doing so. The attacker must know the IP address of the target machine. Although, the attacker can use the client application to perform a search through a range of IP addresses, this is infeasible if the attacker can not narrow the range to a small subset because there are four billion possible IP addresses. A firewall between the target machine and the attacker virtually makes it impossible for the attacker to communicate with the target machine.
Most corporations have firewalls in place.
By following safe computing practices, for example, not downloading or running applications from unknown sources, users can protect themselves from the potential threat.