As an update to yesterday’s post, Gmail is contacting postmasters at domains signing with 512 bit keys to warn them of the upcoming changes. This message also clarifies “DKIM keys failing.” Messages signed with 512 bit keys or less will be treated as unsigned by Gmail in the next week or so. Hello, We noticed that your domain is sending email to Gmail users that is DKIM signed...
Is Google failing DKIM keys shorter than 512 bits?
Today’s Wednesday question comes from Andrew B. and got pushed to Thursday so I could check a few more facts. Have @Gmail yet confirmed the @ReturnPath story that they’ll start failing weak DKIM sigs? RP cites no source: @hey4ndr3w The answer is that no one from Gmail has publicly confirmed that they’re failing to authenticate mail signed with weak DKIM keys. But conversations...
How long is your DKIM key?
While we were at M3AAWG, Wired published an article talking about how simple it was to crack DKIM keys. I didn’t post about it at the time because it didn’t really seem like news. DKIM keys smaller than 1024 are vulnerable and not secure and the DKIM spec does not recommend using keys smaller than 1024. When I asked the DKIM-people-who-would-know they did tell me that the news was...
Get a helmet
There’s been a lot of interesting reaction to Steve’s security post yesterday. A lot of people seem upset that we have pointed out one of the ways that ESPs may be getting compromised. Complaints range from the message being overly simplistic, through to complaints that we just don’t understand how much of an issue security is, through to complaints that we’re not pointing...
Browsers, security and paranoia
MAAWG is coming up and lots of us are working on documents, and presentations. One of the recent discussions is what kind of security recommendations, if any, should we be making. I posted a list of things including “Don’t browse the web with a machine running Windows.” Another participant told me he thought my recommendation to not use a windows machine to browse the web was...
What blogs are you reading besides mine?
It’s been a week. A very, very long week. Which means that at 4 on a Friday I’m grasping at straws for something interesting to write about. So I do what I do when I’m out of ideas, I look through the email related blogs I’m subscribed to. A bunch of them are still active, but there’s a good dozen or so that haven’t been updated in months. I realize I’m...
Is any data safe?
Today another major retailer announced their customer files were compromised. This company had clearly implemented some security that kept hackers from getting too much information. Passwords were hashed and credit card numbers were kept on a separate server, which does signal that the company designed with security in mind. Nevertheless, personal information was compromised. Is there anyway to...
More on Rove Digital
Brian Krebs has more on Rove Digital and the criminal connection to other scammers and spammers.
Biggest botnet takedown to date
Yesterday law enforcement officials arrested 6 people and charged them with running a massive internet fraud ring. Over 4 million PCs were part of the botnet. According to the FBI the cyber ring used a class of malware called DNSChanger to infect approximately 4 million computers in more than 100 countries. There were about 500,000 infections in the U.S., including computers belonging to...
Are you ready for the next attack?
ESPs are under attack and being tested. But I’m not sure much progress in handling and responding to the attacks has been made since the Return Path warning or the Epsilon compromise. Last week a number of email marketers became aware that attacks against ESPs and senders were ongoing. The shock and surprise many people exhibited prompted my Spear Phishing post on Friday. The first round of...