EveryDNS Under Botnet DDoS Attack

mellow marsh writes "EveryDNS, sister company to OpenDNS (which runs the PhishTank anti-phishing initiative), has been hit by a massive distributed denial-of-service attack. The attack started sometime Friday afternoon and, from all indications, was targeting Web sites that used free DNS management services provided by EveryDNS. At the height of the DDoS bombardment, EveryDNS was being hit with more than 400mbps of traffic at each of its four locations around the world. From the article: '"We were collateral damage," Ulevitch explained... Because law enforcement is involved, Ulevitch was hesitant to release details of the actual target but there are signs that some of the targets were "nefarious domains" that have since been terminated.'" OpenDNS, which makes use of EveryDNS services, was affected for a time, until they spread their authoritative DNS more broadly. The EveryDNS site is now reporting that the attack is continuing but has been mitigated and is not affecting operations.

Comments

Re:COM != NET

[SaDan]

What parent said. The main site is http://www.everydns.net/ not .com.

Another quality, editor approved Slashdot story. Great job, guys.

Heh

[davidu]

The site is EveryDNS.Net.

I'll keep it up for Slashdot, let me just move it around a bit. :-)

-david

Questions?

[davidu]

Since I've been getting a lot of questions from folks about EveryDNS, how we've been stable and around so long, how we dealt with this DDoS and how we manage to cover our costs I am writing a response that will probably be posted here on Slashdot tomorrow or Monday to answer all these questions.

If you have questions about this or DDoS in general, feel free to ask them here and I'll make sure to cover them in my response. I'll be writing about what we've seen and what I generally do when it comes to soaking up traffic and how we handled this event in particular. (The short answer: find the smartest people you can to help you and then start taking corrective action)

Thanks!

David Ulevitch

Re:solution to DDOS attack

[sirket]

Not quite- It generally works like this:

First off- be prepared for a damned attack and don't wait til it happens. When an attack does come:

1- Identify the target IP address
2- Immediately null-route traffic for that address (preferably using BGP community based null-routing)
This gets the rest of your systems back up and gives you time to work on the problem.
3- Try to identify a pattern in the attacking traffic- use a product from a company like Mazu- or just tcpdump if you're good with sed and awk.
4- If there is a pattern ask the upstream ISP to block based on that pattern (same source port, same source IP, same TTL, whatever). Or block it yourself if you have the router and bandwidth capacity to deal with the attack yourself- though that's generally a waste of your resources.
5- If there is no pattern but the traffic is malformed then enabled a Cisco Riverguard or similar protection device that can filter out malformed traffic at the higher protocol layers. As an alternative, sign up for such a service form a company like Prolexic.
6- Remove your null route and see how you did.
7- If you can't afford a protection service, you can try moving the host/dns records to new IP's. Sometimes the attacks don't follow- sometimes they do. It's often worth a try as it can be done faster than enabling protection services in many cases. In this case leave the old null route in place until the attack stops. Be prepared for the attack to return at any time once they realize what's happened.

Make sure to keep traffic logs for law-enforcement and to share with other ISP's so that they can track down the offending bots.

In the future try to keep your traffic as segregated as possible such that an attack on a single host will not take down too many other services should you need to null-route that address for an extended period of time.

The easiest solution- block all IP addresses assigned to the APNIC region and watch as your site immediately returns to normal. Sadly most of the DDoS's I've seen recently had the majority of their traffic sourced from APNIC addresses.

-sirket