DDoS / Most Commented

Port 25 Blocking, or Fix SMTP and Leave Port 25 Alone for the Sake of Spam?

Larry Seltzer wrote an interesting article for eWeek, on port 25 blocking, the reasons why it was being advocated, and how it would stop spam. This quoted an excellent paper by Joe St.Sauver, that raised several technically valid and true corollaries that have to be kept in mind when blocking port 25 -- "cough syrup for lung cancer" would be a key phrase... Now, George Ou has just posted an article on ZDNET that disagrees with Larry's article, makes several points that are commonly cited when criticizing port 25 blocking, but then puts forward the astonishing, and completely wrong, suggestion, that worldwide SPF records are going to be a cure all for this problem. Here is my reply to him... more»

IPv6: Extinction, Evolution or Revolution?

For some years now the general uptake of IPv6 has appeared to be "just around the corner". Yet the Internet industry has so far failed to pick up and run with this message, and it continues to be strongly reluctant to make any substantial widespread commitment to deploy IPv6. Some carriers are now making some initial moves in terms of migrating their internet infrastructure over to a dual protocol network, but for many others it's a case of still watching and waiting for what they think is the optimum time to make a move. So when should we be deploying IPv6 services? At what point will the business case for IPv6 have a positive bottom line? It's a tough question to answer, and while advice of "sometime, probably sooner than later" is certainly not wrong, it's also entirely unhelpful as well! more»

A Question of DNS Protocols

One of the most prominent denial of service attacks in recent months was one that occurred in March 2013 between Cloudflare and Spamhaus... How did the attackers generate such massive volumes of attack traffic? The answer lies in the Domain Name System (DNS). The attackers asked about domain names, and the DNS system answered. Something we all do all of the time of the Internet. So how can a conventional activity of translating a domain name into an IP address be turned into a massive attack? more»

Can We Stop IP Spoofing? A New Whitepaper Explores the Issues

In March 2013, Spamhaus was hit by a significant DDoS attack that made its services unavailable. The attack traffic reportedly peaked at 300Gbps with hundreds of millions of packets hitting network equipment on their way. In Q1 2015, Arbor Networks reported a 334Gbps attack targeting a network operator Asia. In the same quarter they also saw 25 attacks larger than 100Gbps globally. What is really frightening about this is that such attacks were relatively easy to mount. more»

Anti-Spoofing, BCP 38, and the Tragedy of the Commons

In the seminal 1968 paper "The Tragedy of the Commons" , Garrett Hardin introduced the world to an idea which eventually grew into a household phrase. In this blog article I will explore whether Hardin's tragedy applies to anti-spoofing and Distributed Denial of Service (DDoS) attacks in the Internet, or not... Hardin was a biologist and ecologist by trade, so he explains "The Tragedy of the Commons" using a field, cattle and herdsmen. more»

The Internet Needs a Security and Performance Upgrade

Many of you will have seen news stories that explained what was going on: a huge DDoS attack on the infrastructure of Dyn had taken down access to many large websites like Twitter. A great deal of digital ink has since been spilled in the mainstream press on the insecurity of the Internet of Things, as a botnet of webcams was being used. Here are some additional issues that might get missed in the resulting discussion. more»

DNS Reflection/Amplification Attack: Proved

Last year there was a "threat" by anonymous group to black out Internet by using DNS Reflection/Amplification attack against the Internet DNS Root servers. I even wrote a little article about it: "End of the world/Internet". In the article I was questioning if this was even possible and what was needed as general interest and curiosity. Well, looking at the "stophaus" attack last week, we are getting some answers. more»

Attack Seriously Slows Two Internet Root Servers

Online attackers have briefly disrupted service on at least two of the 13 "root" servers that are used to direct traffic on the Internet.

The attack, which began Tuesday at about 5:30 a.m. Eastern time, was the most significant attack against the root servers since an October 2002 distributed denial of service (DDOS) attack, said Ben Petro, senior vice president of services with Internet service provider Neustar Inc. more»

ICANN Ordered by Illinois Court to Suspend Spamhaus.org

Apparently, at this stage, it is only a proposed ruling. But I am no lawyer. This story has been discussed before, when Spamhaus, which is located in the UK, was sued in the US by a spammer. They refused to come before the court as "they do no business in Illinois, and are located in the UK...After this court ruling, Spamhaus.org was under a DDoS attack, in my opinion for the purpose of preventing users from reaching the information it provided about the court ruling. This was done along-side a Joe Job, sending fake email appearing to come from Spamhaus's CEO... more»

End of the World/Internet on 31-March-2012?

Well... Maybe not the world, but the Internet it seems. According to a Pastebin letter, Anonymous announced they will black-out Internet on 31st of March. They even explained how to do it by attacking the DNS Root Servers on Internet using a reflected amplification attack. If this is successful, the root DNS servers will become unresponsive and cannot handle any other requests... more»

Thoughts About "Protection Against BIND"

Imagine my surprise upon reading a BBC article which identified ISC BIND as the top security vulnerability to UNIX systems. At ISC, we have striven for a decade to repair BIND's reputation, and by all accounts we have made great progress. "What could this be about," I wondered, as I scanned the BBC article for more details. It turns out that BBC was merely parroting what it had been told by SANS. OK, let's see what SANS has to say... more»

Are Botnets Run by Spy Agencies?

A recent story today about discussions for an official defense Botnet in the USA prompted me to post a question I've been asking for the last year. Are some of the world's botnets secretly run by intelligence agencies, and if not, why not? Some estimates suggest that up to 1/3 of PCs are secretly part of a botnet. The main use of botnets is sending spam, but they are also used for DDOS extortion attacks and presumably other nasty things like identity theft. But consider this... more»

Sorry, Not Sorry: WHOIS Data Must Remain Public

In March, I posted a call to action to those of us in the community who have the inclination to fight against a movement to redact information critical to anti-abuse research. Today, I felt compelled to react to some of the discussions on the ICANN discussion list dedicated to the issue of WHOIS reform: Sorry, not sorry: I work every working hour of the day to protect literally hundreds of millions of users from privacy violating spam, phish, malware, and support scams. more»

Ensuring Maximum Resilience to the DNS?

Yesterday CommunityDNS noticed a sudden, heavy spike in traffic through its Anycast node in Hong Kong. While comfortably processing queries at 863,000 queries per second for close to 2 hours the occurrence was undeniable. While we can't say the increase in traffic was specifically due to DDoS, its sudden increase is suspicious and reminds us that DDoS is still a popular tool used by the malicious community. more»

Report on DNS Amplification Attacks

In this newly released paper Randal Vaughn and Gadi Evron discuss the threat of Distributed Denial of Service (DDoS) attacks using recursive DNS name servers open to the world. The study is based on case studies of several attacked ISPs reported to have on a volume of 2.8Gbps. One reported event indicated attacks reaching as high as 10Gbps and used as many as 140,000 exploited name servers. more»