Noticed Welchie/Nachi in Your Bandwidth Bill, Yet?

Pinkboard Panther asks: "I have recently received my bill for Internet usage for last month and discovered it is 4 times higher than expected. Since there had been no increase in usage of the sites I run I had to search elsewhere for the exorbitant increase. Eventually I tracked it down to my firewall being bombarded with 20,000 ICMP Echo requests a minute from many different IP addresses. This adds up to $A10 per hour or $A240 a day. I still need to battle with my ISP over whether I should be paying for this. It seems that the Welchie/Nachi worm sends out pings to find what machines are out there before it moves onto deeper probes. I can't believe that I am the only site out there which is being attacked in this way. There must be lots of other sites out there who are affected this way. Maybe they just haven't received their bills, yet?"