ICMP question

[cc <cc () belfordhk com>]

Hi,

My firewall has been receiving an inordinate amount of ICMP
pings from external systems.  The strange thing about this
is that the ICMP packets coming to my firewall are actually
ICMP responses and not requests.

I'm still monitoring the network to see if a machine
is pinging any machines outside of the LAN.  At this
moment, I don't see any suspicious useage.

I've looked at the logs (snort) and noticed that some
of these pings originate from *.cirn.net.   Has anyone
heard of this network?

And then, some of these pongs contains a payload
which has the message "Please help me, matrix catch me".
I've been googling and couldn't find anything.
Does anyone have any idea what this ping response
might be?  A bot?

Should I be worried about this?

Any help appreciated.



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