GEN:SID 1:474
Message ICMP superscan echo
Summary This event is generated when an ICMP Echo Request from the Windows based
scanner SuperScan is detected.
Impact Information gathering.
Detailed Information SuperScan is a freely available Windows based scanner from Foundstone.
The scanners default behavior is to send an ICMP Echo Request before
starting the scan. This ICMP packet has a special payload of eight (8) bytes,
consisting of the number zero (0).

This scanner is fairly popular among Windows users.
Affected Systems All
Attack Scenarios SuperScan may be used as an information gathering tool to detect active hosts
on a network by sending icmp echo requests.
Ease of Attack Simple.  SuperScan is widely available.
Corrective Action  
Additional References Foundstone
http://www.foundstone.com/

McAfee:
http://vil.nai.com/vil/content/v_103727.htm