Rule:--Sid:428--Summary:This event is generated when a host generates and ICMP Parameter Problem datagram with an undefined ICMP Code.--Impact:ICMP datagrams should never contain undefined ICMP Codes.  This is normally an indication of nefarious activity occurring on the network.--Detailed Information:A router generates a Parameter Problem message for any error not specifically covered by another ICMP message.  This could be an indication of routing problems on the network, or malfunctioning routing hardware.--Attack Scenarios:None known--Ease of Attack:Numerous tools and scripts can generate this type of ICMP datagram.--False Positives:None known--False Negatives:None known--Corrective Action:ICMP Type 12 datagrams with undefined ICMP Codes are not normal network activity.  Hosts generating these types of datagrams should be investigated for configuration errors or nefarious activity.--Contributors:Original Rule writer unknownSourcefire Research TeamMatthew Watchinski (matt.watchinski@sourcefire.com)--Additional References:None--