Recent Posts

Internet Storm Center on the Spamhaus DOS

The Internet Storm Center (ISC) has a blog post up discussing the DOS attack against Spamhaus. They do confirm they saw traffic approaching 300Gbps against Spamhaus. They also point out that most people probably never knew.

Spamhaus answers about the recent DoS attack

Answers about recent DDoS attack on Spamhaus

More on the attack against Spamhaus and how you can help

While much of the attack against Spamhaus has been mitigated and their services and websites are currently up, the attack is still ongoing. This is the biggest denial of service attack in history, with as much as 300 gigabits per second hitting Spamhaus servers and their upstream links.
This traffic is so massive, that it’s actually affecting the Internet and web surfers in some parts of the world are seeing network slowdown because of this.
While I know that some of you may be cheering at the idea that Spamhaus is “paying” for their actions, this does not put you on the side of the good. Spamhaus’ actions are legal. The actions of the attackers are clearly illegal. Not only is the attack itself illegal, but many of the sites hosted by the purported source of the attacks provide criminal services.
By cheering for and supporting the attackers, you are supporting criminals.
Anyone who thinks that an appropriate response to a Spamhaus listing is an attack on the very structure of the Internet is one of the bad guys.
You can help, though. This attack is due to open DNS resolvers which are reflecting and amplifying traffic from the attackers. Talk to your IT group. Make sure your resolvers aren’t open and if they are, get them closed. The Open Resolver Project published its list of open resolvers in an effort to shut them down.
Here are some resources for the technical folks.
Open Resolver Project
Closing your resolver by Team Cymru
BCP 38 from the IETF
Ratelimiting DNS
News Articles (some linked above, some coming out after I posted this)
NY Times
BBC News
Cloudflare update
Spamhaus dDOS grows to Internet Threatening Size
Cyber-attack on Spamhaus slows down the internet
Cyberattack on anti-spam group Spamhaus has ripple effects
Biggest DDoS Attack Ever Hits Internet
Spamhaus accuses Cyberbunker of massive cyberattack

Some content is just bad; but it doesn't have to be

There are a few segments in the marketing industry that seem to acquire senders with bad mailing practices. Nutraceuticals, male performance enhancing drugs, short term or payday loans and gambling have a lot of senders that treat permission as optional. The content and the industry themselves have garnered a bad reputation.
This makes these industries extremely difficult for mailers who actually have permission to send that content to their recipients. Working with this kind of sender, sometimes it seems impossible to get mail delivered to the inbox, no matter what the level of permission. Even when it’s double confirmed opt-in with a cherry on top, all the care in the world with permission isn’t enough to get inbox delivery.
This doesn’t have to be the case. Look at the porn industry. Early on in the email marketing arena there was a lot of unsolicited image porn. A Lot. So much that complaints by recipients drove many ISPs to disable image loading by default. The legitimate porn companies, though, decided unsolicited image porn was bad for the industry as a whole. Porn marketers and mailers adopted fairly strong permission and email address verification standards.
It was important for the porn marketers that they be able to prove that the person they were mailing actually requested the email. The porn marketers took permission seriously and very few companies actually send photographic porn spam these days. Even the “Russian girls” spam doesn’t have not safe for work images any longer.
Because of their focus on permission, in some cases revolving around age of consent in various jurisdictions, the porn industry as a whole is not looked at as “a bunch of spammers.” Porn content isn’t treated as harshly as “your[sic] pre-approved for a wire transfer” or “best quality drugs shipped overnight.”
Just having offensive content isn’t going to get you blocked. But having content that is shared by many other companies who don’t care about permission, will cause delivery headache after delivery headache. This is true even when you are the One Clean Sender in the bunch.

Questioning standards

M³AAWG publishes documents summarizing and discussing current practices for stopping and preventing abuse. Some of these documents are focused on ISPs while others are focused on marketers. While M³AAWG is not directly nor officially a standards body, most of the documents have been written by members and reflect the best current practices for that document.
Members have been asked to leave the organization and some companies are denied membership because they are not in line with the organizational values. Some of these companies are ESPs or marketers, but some of these companies have been ISPs as well.
The standards written by M³AAWG are challenging for a lot of marketers to follow. These standards are written with the input of senders, but they all comply with the M³AAWG mission of stopping messaging abuse. Many ISPs believe that unsolicited email is abuse, thus M³AAWG standards say that all mail needs to be sent to recipients who request that mail. Purchasing lists, selling lists, and appending email addresses are all unacceptable activities for M³AAWG members.
I never really had much concern about the effectiveness of the M³AAWG process. Most of the big industry players are there and many of the ISPs have an aggressive anti-abuse attitude.
But last week I saw a blog post on a fairly major industry blog that listed a bunch of (made up, tasteless and sexist) things “overheard” at the recent M3AAWG conference (it’s been removed and I wouldn’t link to it anyway). The blog post made it look like no real work gets done at M3AAWG and that the attendees don’t work at the conference. I won’t claim that it’s a staid and quiet conference, but most attendees work very hard during the day.
The next day, the author tweeted:

Spamhaus answers questions

Lost in all of the DOS attack news this week is that the first installment of Spamhaus answering questions from marketers in Ken Magill’s newsletter.
It’s well worth a read for anyone who is interested in hearing directly from Spamhaus.
One quote stood out for me, and it really sums up how I try to work with clients and their email programs.

CBL website and email back on line

The CBL website is back on line.
It’s possible that your local DNS resolver has old values for it cached. If so, and if you can’t flush your local DNS cache, and you really can’t wait until DNS has been updated then you may be able to put a temporary entry in your hosts file to point to cbl.abuseat.org.
You can get the IP address you need to add by querying the nameserver at ns-2038.awsdns-62.co.uk for cbl.abuseat.org. No, I’m not going to tell you the IP address – if you can’t do a basic DNS query, you shouldn’t be modifying your hosts file and you can just wait a day.

dDOS spreads to the CBL

Spamhaus has mostly mitigated the dDOS against the Spamhaus website and mailserver, but now the CBL is under attack. They have been working to get that under protection as well, but it’s taking some time.
Right now there are no public channels for delisting from the CBL. The Spamhaus Blog will be updated as things change, and I’ll try and keep things updated here as well.
UPDATE: Cloudflare talks about the scope of the attack

Mail that looks good on desktop and mobile

Over the weekend I noticed a new CSS framework aimed at email rather than web development, “Antwort“.
This isn’t the first or only framework for email content, but this one looks simple and robust, and it allows for content that doesn’t just adapt for different sized displays but looks good on all of them. The idea behind it is to divide your content into columns, magazine style, then display the columns side-by-side on desktop clients and top to bottom on mobile clients. That opens up much more interesting designs than the more common single fluid column approach.

It looks nice, it supports pretty much every interesting email client, but it also comes with some directions based on real world experience.

Spamhaus under major dDOS

Late last night I, and a number of other folks, received mail from Spamhaus informing us of a major denial of service attack against their servers. The attack is so bad that the website and main mailserver is currently offline.
DNS services, including rsync and the mirrors, are up and running.
Spamhaus is working to bring the mailserver and website back up, and are hoping to have it up later today.
If there are any critical or particularly urgent SBL issues today, contact your ESP delivery team. The folks who were contacted do have an email address for urgent issues. This is not an address for routine queries, however, and most listees are going to have to wait until normal services are restored to have their listing addressed.
If there is something particularly urgent and your ESP or delivery team does not have a contact address, you can contact me an I can see what I can do.
UPDATE: Most of the IPs people have sent me are actually XBL/CBL listings. But right now the CBL webserver is responding slowly due to the DOS.
If you want to look up a listing without using the Spamhaus website you can use the “host” or “dig” command line tools. To do this reverse the digits in the IP address and append zen.spamhaus.org on the end.
So for the IP 10.11.12.13 you would query 13.12.11.10.zen.spamhaus.org