Cyberattack / Most Viewed

Trench Warfare in the Age of The Laser-Guided Missile

The historical development of spam fighting is allowing computer-aware criminals to take the upper hand in the fight against what has now evolved into a completely technologically and organizationally merged threat to public safety. If we do not change our strategic approach immediately, the battle, indeed even the war may be all but lost... Of late, much has been said in the popular and computer press about a vector that is annoying, but hardly critical in nature: 'Image spam'. Spammers have jumped on the new technology of 'image-only' payloads, which morph one pixel per message, rendering them unique, and traditional check-sum blocking strategies ineffective... Fortunately this fraudulent stock-touting scheme leaves a paper trail that has allowed for some successful prosecutions in the latter half of the year. Stock spamming, while popular at present time is likely to decline as legal actions increase... more»

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»

Where are DNS Root Servers? See them on Google Maps

DNS root servers function as part of the Internet backbone, as explained in Wikipedia, and have come under attack a number of times in the past -- although none of the attacks have ever been serious enough to severely hamper the performance of the Internet. In response to some of the common misconceptions about the physical location and total number of DNS root servers in the world, Patrik Faltstrom has put together a visual map on Google, pin-pointing the approximate location of each server around the world. more»

Examining Two Well-Known Attacks on VoIP

VoIP is here to stay. In fact many incumbent telecommunication carriers have started offering VoIP service for sometime and several new VoIP service providers have emerged. Aside from issues such as quality of service, the aspect of security, or lack thereof, is misunderstood by some of the VoIP service providers. This purpose of this article is to discuss two of the most well known attacks that can be carried out in current VoIP deployments. more»

So You Think You're Safe from DNS Cache Poisoning?

Everyone is probably well aware of the Kashpureff-style DNS cache- poisoning exploit (I'll call this "classic cache poisoning"). For reference, see the original US-CERT advisory prompted by this exploit. Vendors patched their code to appropriately scrub (validate) responses so that caches could not be poisoned. For the next 7-8 years, we didn't hear much about cache poisoning. However, there was still a vulnerability lurking in the code, directly related to cache poisoning. ...On April 7, 2005, the SANS ISC (not to be confused with Internet Systems Consortium) posted an update detailing how Microsoft Windows DNS servers were still being poisoned, even though the "Secure cache against pollution" option was set. The SANS ISC found that Windows DNS servers using BIND4 and BIND8 servers as forwarders were being poisoned. But how could this be? 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»

Internet Security Marketing: Buyer Beware

As security breaches increasingly make headlines, thousands of Internet security companies are chasing tens of billions of dollars in potential revenue. While we, the authors, are employees of Internet security companies and are happy for the opportunity to sell more products and services, we are alarmed at the kind of subversive untruths that vendor "spin doctors" are using to draw well-intentioned customers to their doors. Constructive criticism is sometimes necessarily harsh, and some might find the following just that, harsh. But we think it's important that organizations take a "buyers beware" approach to securing their business. more»

DNSSEC: Once More, With Feeling!

After looking at the state of DNSSEC in some detail a little over a year ago in 2006, I've been intending to come back to DNSSEC to see if anything has changed, for better or worse, in the intervening period... To recap, DNSSEC is an approach to adding some "security" into the DNS. The underlying motivation here is that the DNS represents a rather obvious gaping hole in the overall security picture of the Internet, although it is by no means the only rather significant vulnerability in the entire system. One of the more effective methods of a convert attack in this space is to attack at the level of the DNS by inserting fake responses in place of the actual DNS response. more»

Defending Networks Against DNS Rebinding Attacks

DNS rebinding attacks are real and can be carried out in the real world. They can penetrate through browsers, Java, Flash, Adobe and can have serious implications for Web 2.0-type applications that pack more code and action onto the client. Such an attack can convert browsers into open network proxies and get around firewalls to access internal documents and services. It requires less than $100 to temporarily hijack 100,000 IP addresses for sending spam and defrauding pay-per-click advertisers. Everyone is at risk and relying on network firewalls is simply not enough. In a paper released by Stanford Security Lab, "Protecting Browsers from DNS Rebinding Attacks," authors Collin Jackson, Adam Barth, Andrew Bortz, Weidong Shao, and Dan Boneh provide ample detail about the nature of this attack as well as strong defenses that can be put in place in order to help protect modern browsers. 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»

Security by Obscurity?

Ah yes, 'Security by obscurity': "Many people believe that 'security through obscurity' is flawed because... secrets are hard to keep." I'm glad the guys guarding the A Root Servers are up on the latest security trends. Of course, you could hide the A Root Servers at the heart of the Minotaur's maze, but they're still going to be "right over there" in cyberspace, at more»

The Case Against DNSSEC

I was talking to my good friend Verner Entwhistle the other day when he suddenly turned to me and said "I don't think we need DNSSEC". Sharp intake of breath. Transpired after a long and involved discussion his case boiled down to four points: 1. SSL provides known and trusted security, DNSSEC is superfluous, 2. DNSSEC is complex and potentially prone to errors, 3. DNSSEC makes DoS attacks worse, 4. DNSSEC does not solve the last mile problem. Let's take them one at a time... 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,, and the OpenRBL. 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 is spamming and blocked mail from 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»