Rule: -- Sid: 231 -- Summary: This event is generated when a pong packet for the Trinoo (aka trin00) DDos suite is detected. -- Impact: This may indicate a compromised system or be the prelude to a Distributed Denial of Service (DDoS) attack. -- Detailed Information: Once a Trinoo client has been installed on a compromised machine and a master is ready and listening, the master sends a "png" (ping) command to its drones in an attempt to enumerate the drone network. A functioning client will respond to port 31335/udp with the text "PONG". Once a machine becomes part of a trin00 network, a Denial of Service (DoS) is typically initiated against one (or more) victim machines. -- Affected Systems: -- Attack Scenarios: As part of a large scale attack against a machine or a network, an attacker will compromise large numbers of machines which will form the army that the trin00 master daemon will command. The master daemon typically instructs the clients to send mass-quantities of packets to a set of victim hosts. If the traffic is sufficient, the victim machines will become resource deprived and thus endure a DoS condition. -- Ease of Attack: Simple. Trinoo client and master programs are widely available. -- False Positives: None Known -- False Negatives: None Known -- Corrective Action: Disconnect infected machine(s) from the network immediately. Use software to determine if a host has been compromised using a rootkit. -- Contributors: Original rule writer unknown Snort documentation contributed by Jon Hart <warchild@spoofed.org> Sourcefire Vulnerability Research Team Nigel Houghton <nigel.houghton@sourcefire.com> -- Additional References: SANS: http://www.sans.org/newlook/resources/IDFAQ/trinoo.htm --
