North American Network Operators Group
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Re: Monumentous task of making a list of all DDoS Zombies.

  • From: Suresh Ramasubramanian
  • Date: Sat Feb 07 23:57:18 2004 
Wayne Gustavus (nanog) wrote:
http://cbl.abuseat.org

Interesting approach. It would be conceivable that if this resource was
Widely used, miscreants could use this service to DDoS there victims without
an army of zombies :-) I still submit that it is more advisable to address
the root of the problem by finding the true host that generated attack
traffic. Automating this process of matching dynamic IP to customer acct with a timestamp and remediation is the goal.
Timestamps are, of course, a solution - they definitely help in quickly identifying compromised hosts.

Another thing that helps with easier identification is a practice some ISPs have of inserting the MAC address of the host into the reverse DNS record, with a short TTL. When a new host gets that IP, the MAC address changes too. I have seen at least one ISP do this - and it makes it a whole lot easier for the ISP to quickly identify the host, rather than having to trawl through RADIUS logs or whatever else.

Then, there's the little matter of ISPs implementing ingress filtering as per BCP38 / RFC 2827. These DDoS zombies seem to also be used as a ready source of spoofed source addresses for attacks.

srs