Unusual entry in Log files

Over the last few days I have suddenly seen lots of these messages in the log files. I'm using ESS 4.2.22.0 on Windows 7 Ultimate 64 Bit.

192.168.1.100 is the IP address of my PC and 192.168.1.107 is the IP address of my Netgear ReadyNAS Duo. Any ideas why my PC would suddenly start generating Covert Channel Exploits and what are they ?

07/03/2010 14:23:03 Detected covert channel exploit in ICMP packet 192.168.1.100 192.168.1.107 ICMP
07/03/2010 14:23:02 Detected covert channel exploit in ICMP packet 192.168.1.100 192.168.1.107 ICMP
07/03/2010 14:23:02 Detected covert channel exploit in ICMP packet 192.168.1.100 192.168.1.107 ICMP
07/03/2010 14:23:02 Detected covert channel exploit in ICMP packet 192.168.1.100 192.168.1.107 ICMP
07/03/2010 14:23:01 Detected covert channel exploit in ICMP packet 192.168.1.100 192.168.1.107 ICMP
07/03/2010 14:23:01 Detected covert channel exploit in ICMP packet 192.168.1.100 192.168.1.107 ICMP
07/03/2010 14:09:59 Detected covert channel exploit in ICMP packet 192.168.1.100 192.168.1.107 ICMP
07/03/2010 14:09:59 Detected covert channel exploit in ICMP packet 192.168.1.100 192.168.1.107 ICMP
07/03/2010 14:09:58 Detected covert channel exploit in ICMP packet 192.168.1.100

 

Have you recently installed a network-aware application that might take advantage of sending its own data within ICMP packets?