This indicates that an mstream agent is responding to an mstream handler ping request.
mstream is a Distributed Denial-of-Service (DDoS) tool. mstream agents use UDP port 6838 to contact their handlers. mstream handlers coordinate the agents to launch DDoS attacks.
Any unprotected system connected to the network is vulnerable to the attack.
The compromised network faces potential DDoS attack.
Apply anti-virus protection to vulnerable system
Clean the compromised host.