GEN:SID 1:244
Message DDOS mstream handler to agent
Summary This event is generated when a DDoS mstream handler directs an mstream agent to begin an attack against a specified target.
Impact  
Detailed Information The mstream DDoS uses a tiered structure of compromised hosts to coordinate and participate in a distributed denial of service attack.  There are "handler" hosts that are used to coordinate the attacks and "agent" hosts that launch the attack.  A handler can direct a particular agent to attack a target. It directs the agent by sending it a UDP packet to destination port 10498 with a string of "stream/" in the payload.  The target IP and duration of the attack will also be included in the payload.
Affected Systems Any mstream compromised host.
Attack Scenarios After a host becomes an mstream agent, it will likely be directed to participate in a DDoS attack.
Ease of Attack Simple. mstream code is freely available.
Corrective Action Perform proper forensic analysis on the suspected compromised host to discover the means of compromise.

Rebuild a confirmed compromised host.

Use a packet-filtering firewall to block inappropriate traffic to the network to prevent hosts from being compromised.
Additional References CVE:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2000-0138
Rule References cve: 2000-0138