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A Fundamental Look at DNSSEC, Deployment, and DNS Security Extensions

In looking at the general topic of trust and the Internet, one of the more critical parts of the Internet's infrastructure that appears to be a central anchor point of trust is that of the Domain Name Service, or DNS. The mapping of "named" service points to the protocol-level address is a function that every Internet user relies upon, one way or another. The ability to corrupt the operation of the DNS is one of the more effective ways of corrupting the integrity of Internet-based applications and services. If an attacker can in some fashion alter the DNS response then a large set of attack vectors are exposed. ...The more useful question is whether it is possible to strengthen the DNS. The DNS is a query -- response application, and the critical question in terms of strengthening its function is whether it is possible to authenticate the answers provided by the DNS. DNSSEC provides an answer to this question. more

Does the Internet Need to be Governed?

The term "Internet Governance" has become an area of particular attention in part as a consequence of widespread recognition that the Internet represents an important area of national interest for all countries seeking to participate in the benefits of global electronic commerce, distance learning, access to the encyclopedic wealth of information on the Internet, and in the social dimension that the Internet is creating. From the perspective of governments, the Internet is simultaneously a technology that promises high economic value for parties making use of it and a challenge in that it is unlike all other telecommunications media previously invented. more

The Anti-Phishing Consumer Protection Act of 2008

Last week Sen. Snowe filed bill S.2661, the Anti-Phishing Consumer Protection Act of 2008, or APCPA. While its goals are laudable, I have my doubts about some of the details. The first substantive section of the bill, Section 3, makes various phishy activities more illegal than they are now in its first two subsections. It makes it specifically illegal to solicit identifying information from a computer under false pretenses, and to use a domain name that is deceptively similar to someone else's brand or name on the web in e-mail or IM to mislead people... more

SPF Loses Mindshare

MAAWG is the Messaging Anti-Abuse Working group. It was started by Openwave, a vendor that sells e-mail hardware and software to large ISPs and originally consisted only of Openwave customers, but has evolved into an active forum in which large ISPs and software vendors exchange notes on anti-spam and other anti-abuse activities. Members now include nearly every large ISP including AOL, Earthlink, Yahoo, Comcast and Verizon is a member, along with ESPs like Doubleclick, Bigfoot, and Checkfree, and vendors like Ciscom, Ironport, Messagelabs, Kelkea/Trend, and Habeas. They've also been quietly active in codifying best practices and working on some small but useful standards like a common abuse reporting format. more

Yahoo, Gmail, Hotmail Compromised - But How?

One of the bigger news stories is that of 10,000 usernames and passwords of Hotmail users were posted this past week, victims of a phishing scam... It seems unlikely to me that this would be a hack where someone would break into Hotmail's servers and access the account information that way. It is much more likely that the spammers got the information by social engineering. Why is this more likely? For one, they'd have to get past all of the firewalls and security measures that Microsoft/Hotmail have to keep intruders out. more

Fight Spam With the DNS, Not the CIA

It seems like spam is in the news every day lately, and frankly, some of the proposed solutions seem either completely hare-brained or worse than the problem itself. I'd like to reiterate a relatively modest proposal I first made over a year ago: Require legitimate DNS MX records for all outbound email servers.

MX records are one component of a domain's Domain Name System (DNS) information. They identify IP addresses that accept inbound email for a particular domain name. To get mail to, say, linux.com, a mail server picks an MX record from linux.com's DNS information and attempts to deliver the mail to that IP address. If the delivery fails because a server is out of action, the delivering server may work through the domain's MX records until it finds a server that can accept the mail. Without at least one MX record, mail cannot be delivered to a domain.
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Sender Address Verification: Still a Bad Idea

A lot of spam uses fake return addresses. So back around 2000 it occurred to someone that if there were a way to validate the return addresses in mail, they could reject the stuff with bad return addresses. A straightforward way to do that is a callout, doing a partial mail transaction to see if the putative sender's mail server accepts mail to that address. This approach was popular for a few years, but due to its combination of ineffectiveness and abusiveness, it's now used only by small mail systems whose managers don't know any better. What's wrong with it? more

Hypertext Mail Protocol (a.k.a. Stub Email): A Proposal

Back in the days of dial-up modems and transfer speeds measured in hundreds of bits per second, unwanted email messages were actually felt as a significant dent in our personal pocketbooks. As increases in transfer speeds outpaced increases in spam traffic, the hundreds of unwanted emails we received per week became more of a nuisance than a serious financial threat. Today sophisticated spam filters offered by all major email providers keep us from seeing hundreds of unwanted emails on a daily basis, and relatively infrequently allow unwanted messages to reach our coveted Inboxes. So, to some degree, the spam problem has been mitigated. But this "mitigation" requires multiple layers of protection and enormous amounts of continually-applied effort. 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

Who Is Blocking WHOIS? Part 2

We have just returned from the Brussels, Belgium ICANN meeting where we released our Registrar audit, the Internet "Doomsday Book." There are many topics covered in the report, but we wanted to follow up specifically on the issue of WHOIS access and add data to our previous column Who Is Blocking WHOIS? which covered Registrar denial of their contracted obligation to support Port 43 WHOIS access. more

The Future of Some Email May Not Use Email

Paul McNamara quotes me extensively in this piece on the EFF protest of Goodmail. When I say "the EFF has lost its mind", i really mean "the EFF has lost its way". In the early days, the EFF was about preventing the government from ruining the Internet commons, and preventing the government from putting walls on the frontier. These days, the EFF is more about preventing companies who have no power to regulate from doing things the EFF doesn't like. That is a huge change, and one that makes the EFF much less worthy of support... more

Wall Street Journal Article on Whois Privacy

Today's Wall Street Journal discusses the fight over Whois privacy. The article on the front page of the Marketplace section starts by discussing how the American Red Cross and eBay use the Whois database to track down scammers: "Last fall, in the wake of Hurricane Katrina, the American Red Cross used an Internet database called "Whois" that lists names and numbers of Web-site owners to shut down dozens of unauthorized Web sites that were soliciting money under the Red Cross logo. Online marketplace eBay Inc. says its investigators use Whois hundreds of times a day..." 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

Comments on an IP Address Trading Market

With IPv4 addresses becoming scarcer, there has been talk that a trading market will develop. The idea is that those holding addresses they do not really need will sell them for a profit. More alarming is that there have been a few articles about how the Regional Internet Registries (RIR) are contemplating creating such a market so that they can regulate it, conceding that it will happen anyway and taking the "if you can't be 'em, join 'em" attitude. This is all a bit disturbing. Maybe I'm na├»ve, but it's a little unclear to me how an unsanctioned trading market could really operate without the RIRs at least being aware... more

Moving Target: Spammer Using Over 1000 Home Computers as DNS

Some individual appears to have hijacked more than a 1,000 home computers starting in late June or early July and has been installing a new Trojan Horse program on them. The Trojan allows this person to run a number of small websites on the hijacked home computers. These websites consists of only a few web pages and apparently produce income by directing sign-ups to for-pay porn websites through affiliate programs. Spam emails messages get visitors to come to the small websites.

To make it more difficult for these websites to be shut down, a single home computer is used for only 10 minutes to host a site. After 10 minutes, the IP address of the website is changed to a different home computer... more