DDoS / Most Viewed

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»

New Instance of DNS Root Server Makes Internet History

For the first time in Internet history the number of instances of DNS root servers outside the United States has overtaken the number within. The balance was tipped by the recent launch in Frankfurt of an anycast instance of the RIPE NCC operated K-root server. The K-root server is one of the 13 DNS root servers that resolve lookups for domain names all over the world and form a critical part of the global Internet infrastructure. The K-root server has been operated by the RIPE NCC since 1997 when the first server was installed at the London Internet Exchange (LINX) in London, UK. 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»

Network Solutions Under Large Scale DDoS Attack, Millions of Websites Potentially Unreachable

Network Solutions is having problems with "all" its name servers, according to their tech support and a recent post on North American Network Operators' Group (NANOG) mailing list indicates that it has been under very large-scale UDP/53 DDoS attack for the last 48 hour period. As a result, domain names hosted with Network Solutions' Worldnic have been affected. Network Solutions is one of the leading domain registrars and DNS hosting providers in the world, managing more than 7.6 million domain names. more»

Internet Attacks Against Georgian Websites

In the last days, news and government web sites in Georgia suffered DDoS attacks. While these attacks seem to affect the Georgian Internet, it is still there... Up to the Estonian war, such attacks would be called "hacker enthusiast attacks" or "cyber terrorism" (of the weak sort). Nowadays any attack with a political nature seems to get the "information warfare" tag. When 300 Lithuanian web sites were defaced last month, "cyber war" was the buzzword. Running security for the Israeli government Internet operation and later the Israeli government CERT such attacks were routine... more»

DNS Gets A Formal Coordination System

CircleID recently interview Paul Vixie, Founder & Chairman of Internet Software Consortium (ISC), to discuss ISC's newly formed Operations, Analysis, and Research Center (OARC). OARC is launched in response to DDoS attacks at the Internet's core infrastructure and the vital requirement for a formal coordination system. OARC is also a part of US homeland security initiatives, such as the formation of Information Sharing and Analysis Centers (ISACs).

"Registries and registrars, ccTLD operators, large corporate NOCs, ISPs and ecommerce companies that host many domain names are all likely candidates. This is also a natural for law enforcement groups that are worried about attacks on the Internet." more»

Blacklists Down from Fear of DDoS

Yet another DNS blacklist has been taken down out of fear of the DDoS attacks that took down Osirusoft, Monkeys.com, and the OpenRBL. Blackholes.compu.net suffered a Joe-Job (A Joe-Job is essentially spam designed to look like it's coming from someone else.) earlier this week. Apparently the Joe-Jobing was enough to convince some extremely ignorant mail administrators that Compu.net is spamming and blocked mail from compu.net. Compu.net has also seen the effects of DDoS attacks on other DNS blacklist maintainers. They've decided that the risk to their actual business is too great and they are pulling the plug on their DNS blacklist before they come under the gun by spammers. 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»

Blacklisting Under Wrong Assumptions

If you analyze the relay of spam- and malware-containing email circulating on the Internet purely through your mail server logs (running the Unix command "tail"), a large proportion seem to come from Asia Pacific hosts, especially those from mainland China. Therefore, many less-experienced systems administrators have simply blocked the access from subnets of Chinese or Asian origin, effectively destroying the fabric of the Internet -- messaging. If administrators took pains to analyze these supposedly Asian spam messages by analyzing the full Internet headers, they would have realized that the Asian servers were merely used by the real spammers as open relays, or perhaps as zombie hosts previously infected with the mass mailing worms through the exploitation of operating system vulnerabilities.  more»

Preventing Future Attacks: Alternatives In DNS Security Management - Part II

In Part I of this article I set the stage for our discussion and overviewed the October 21st DDoS attacks on the Internet's 13 root name servers. In particular, I highlighted that the attacks were different this time, both in size and scope, because the root servers were attacked at the same time. I also highlighted some of the problems associated with the Domain Name System and the vulnerabilities inherent in BIND. Part II of this article takes our discussion to another level by critically looking at alternatives and best practices that can help solve the security problems we've raised. more»

Phone Always Busy? Must be DDoS on VoIP Network

Amidst the fascinating news from the SCO saga, preparing for SANS London and contributing to the Unix timeline project at Grokline my eyes caught a piece of rather distressing news on the BBC. It appears that BT (British Telecom) intends to move its current phone network to an IP-based network by 2009 thereby sending the circuit-switched technology off to the attic. The real question is: can we guarantee the same level of reliability on VoIP as we had on circuit-switched telephony when the stated aim is to carry both voice and data traffic down the same cables (or fibres more likely)? more»

Cyber Crime: An Economic Problem

During ISOI 4 (hosted by Yahoo! in Sunnyvale, California) whenever someone made mention of RBN (the notoriously malicious and illegal bulletproof hosting operation, the Russian Business Network) folks would immediately point out that an operation just as bad was just "next door" (40 miles down the road?), working undisturbed for years. They spoke of Atrivo (also known as Intercage). The American RBN, if you like... 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»

IPv6 Adoption Brings New Security Risks

Although IPv6 DDoS attacks are not yet a common occurrence, there are indications that malicious actors have started testing and researching IPv6 based DDoS attack methods. more»

Industry Updates

Attacks Decrease by 23 Precent in 1st Quarter While Peak Attack Sizes Increase: DDoS Trends Report

Verisign Releases Q4 2016 DDoS Trends Report: 167% Increase in Average Peak Attack from 2015 to 2016

Verisign Q3 2016 DDoS Trends Report: User Datagram Protocol (UDP) Flood Attacks Continue to Dominate

Don't Gamble With Your DNS

Defending Against Layer 7 DDoS Attacks

How Savvy DDoS Attackers Are Using DNSSEC Against Us

Verisign Q1 2016 DDoS Trends: Attack Activity Increases 111 Percent Year Over Year

Is Your TLD Threat Mitigation Strategy up to Scratch?

Resilient Cybersecurity: Dealing with On-Premise, Cloud-Based and Hybrid Security Complexities

Verisign Releases Q4 2015 DDoS Trends - DDoS Attack Activity Increasing by 85% Year Over Year

Neustar Data Identifies Most Popular Times of Year for DDoS Attacks in 2015

The Framework for Resilient Cybersecurity (Webinar)

Verisign Mitigates More Attack Activity in Q3 2015 Than Any Other Quarter During Last Two Years

Faster DDoS Mitigation - Introducing Verisign OpenHybrid Customer Activated Mitigation

Verisign's Q2'15 DDoS Trends: DDoS for Bitcoin Increasingly Targets Financial Industry