Rule:

--
Sid:
369

--
Summary:
This event is generated when an ICMP echo request is made from a BayRS Router.

--
Impact:
Information gathering.  An ICMP echo request can determine if a host is active.

--
Detailed Information:
An ICMP echo request is used by the ping command to elicit an ICMP echo reply from a listening live host.  An echo request that originates from a BayRS router contains a unique payload in the message request.  

--
Affected Systems:
All

--
Attack Scenarios:
An attacker may attempt to determine live hosts in a network prior to launching an attack.

--
Ease of Attack:
Simple

--
False Positives:
An ICMP echo request may be used to legimately troubleshoot networking problems.

--
False Negatives:
None known.

--
Corrective Action:
Block inbound ICMP echo requests.

--
Contributors:

Original rule written by Doug@Minderhout.com  
Modified by Brian Caswell <bmc@sourcefire.com>
Documented by Steven Alexander<alexander.s@mccd.edu>
Sourcefire Research Team
Judy Novak <judy.novak@sourcefire.com>

--
Additional References:

Bugtraq
http://www.whitehats.com/info/IDS444

--
