Something very weird is going on - krebsonsecurity.com is resolving to 127.0.0.1 . Could this be an attempt by someone's DNS servers to make the machines in the original attacking botnet DoS themselves?
My ISP's resolver has them too. Apparently it's somewhat common for ISP-run resolvers to impose minimum TTLs (the nominal TTL on the record I get is 5 minutes).
This seems like an ineffectual measure. Instead of giving the domain to the individual nodes in the DDoS. I'd resolve it once and pound the IP until it changes.
With a simple script curling the page and looking at the content to check if it's pointed to the right server. Ignoring unroutable or inane IPs returned by the DNS.