ESP attacks, again. Be wary.

There seems to be an uptick in phishing attacks that have an impact on ESPs recently.
Your CEO
The most critical one is targeted spear-phishing attacks that claim to be internal documents sent by senior staff within the company, e.g. from the company CEO.
It’s likely that the attached documents will compromise and backdoor your machine, and from their most of your internal network, using an infected document to load a remote administration tool (RAT) such as Netwire.
Be very, very wary of document attachments, especially in generic looking emails that you weren’t expecting, from senior people. Making sure your antivirus signatures are up to date is a great idea, but nothing will protect you as effectively as not opening the infected documents.
Your domain registrar
The other campaign I’m aware of is emails that claim to be abuse reports from registrars (e.g. opensrs, tucows, etc) aimed at domain registration contacts, claiming that a domain has been suspended and that the recipient should click on a link to “download a copy of complaints received”.
e.g.

Dear Steve Atkins,
The Domain Name ABUSEMONKEY.COM have been suspended for violation of the TUCOWS, INC. Abuse Policy.

or

Dear Sir/Madam,
The following domain names have been suspended for violation of the TUCOWS, INC. Abuse Policy:
Domain Name: KNOWYOURDELIVERY.COM
Registrar: TUCOWS, INC.
Registrant Name: Steve Atkins
SPF debugging
All About Email: Q & A session tomorrow

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We're all targets

Last week, another email provider announced their systems had a security incident. Mandrill’s internal security team detected unusual activity and took the servers offline to investigate. While there’s no sign any data was compromised or servers infiltrated, Mandrill sent an email to their customers explaining the incident was due to a firewall rule change.
Email service providers are a high value target for hackers, even if all they have is email addresses. Selling the email addresses is extremely profitable for hackers who can either sell the list outright or sell access to the list. In addition to gaining access to the email addresses, hackers often use the ESP to send these messages essentially stealing the ESP’s reputation to deliver the spam.
It was just over four years ago when a number of major ESPs were targets of a large attack and multiple ESPs were compromised. Earlier this month, three people were arrested for their roles in the attack. While the attacks four years ago were primarily spear phishing attacks, the security incident at Mandrill shows that hackers and botnets are actively probing the ESP’s network looking for access or known vulnerabilities. Spear phishing is an attempt to gain unauthorized access to a system by specifically targeting an individual, group, or organization. The scam attempts to have the user to click a link to infect their computer and network or capture their user id and password via a fake website. The scam email may appear to be sent from the company’s security or human resources department, but the email is either forged or another user’s account has been compromised.
Just because recent arrests have been made does not mean the threat is over. Systems often change, are upgraded, and are integrated with many additional services and systems can become vulnerable.  Security will never be a set and forget policy. In the last 12 months there has been two significant vulnerabilities discovered, first Heartbleed and second was POODLE. Security professionals from all industries had to react quickly to secure their systems and hackers immediately began probing for systems that were unpatched. GFI reports there were over 7,000 vulnerabilities discovered in 2014 with 24% of them being rated as high severity. Security must not only cover servers, but the transmission of the data internally and with third-party vendors, and the workstations of employees.
IT and security professionals must be ever vigilant in protecting their network and their customers data. SANS Institute provides a number of security control best practices including a document on Data Protection. The control recommendations range from quick wins to advanced considerations such as monitoring all traffic leaving the organization and being able to detect any unauthorized or unusual transfer of data, blocking access to file transfer protocols and file sharing websites, performing annual reviews of all keys, certifications, and security procedures.
One of the best ways to help the entire industry to be secure is to be transparent and open when incidents happen. Mandrill has published a blog post with the results of their investigation.

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Compromises and phishing and email

Earlier this month, Sendgrid reported that a customer account was compromised and used for phishing. At the time Sendgrid thought that it was only a single compromise. However, they did undertake a full investigation to make sure that their systems were secure.
Today they released more information about the compromise. It wasn’t simply a customer account, a Sendgrid employee’s credentials were hacked. These credentials allowed the criminals to access customer data, and mailing lists. Sendgrid has a blog post listing things customers should do and describing the changes they’re making to their systems.
Last month it was Mandrill. Today it’s Sendgrid. It could be anyone tomorrow.
Security is hard, there’s no question about it. Users have to have access. Data has to be transferred. Every user, every API, every open port is a way for a bad actor to attempt access.
While it wasn’t said directly in the Sendgrid post, it’s highly likely that the employee compromise was through email. Most compromises go back to a phish or virus email that lets the attacker access the recipient’s computer. Users must be ever vigilant.
We, the email industry, haven’t made it easy for users to be vigilant. Just this weekend my best friend contacted me asking if the email she received from her bank was a phishing email. She’s smart and she’s vigilant, and she still called the number in the email and started the process without verifying that it was really from the bank. She hung up in the transaction and then contacted me to verify the email.
She sent me headers, and there was a valid DMARC record. But, before I could tell her it wasn’t a phishing email, I had to go check the whois record for the domain in question to make sure it was the bank. It could have been a DMARC authenticated email, but not from the bank. The whois records did check out, and the mail got the all clear.
There’s no way normal people can do all this checking on every email. I can’t do it, I rely on my tagged addresses to verify the mail is legitimate. If the mail comes into an address I didn’t give the sender, then it’s not legitimate – no matter what DMARC or any other type of authentication tells me. But most people don’t have access to tagged or disposable addresses.
I don’t know what the answers are. We really can’t expect people to always be vigilant and not fall for phishing. We’re just not all present and vigilant every minute of every day.
For all of you who are going to tell me that every domain should just publish a p=reject statement I’ll point out DMARC doesn’t solve the phishing problem. As many of us predicted, phishers just move to cousin and look alike domains. DMARC may protect citi.com, but citimarketingemail.com or citi.phisher.com isn’t.
We’ve got to do better, though. We’ve got to protect our own data and our customer’s data better. Email is the gateway and that means that ESPs, with their good reputations and authentication, are prime targets for criminals.

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Disposable addresses

Both Steve and I have blogged about how we use tagged addresses to monitor and manage our incoming mail. This is not something unique to our system, but rather a feature that’s existed in many mail systems for a long time. Many unix systems support tagged addresses out of the box, but there are also commercial MTAs and even some webmail services that support tags.
Gmail offers “+ addressing” where users can use unique tags after their username. This gives every gmail use an unlimited number of addresses to use. Any address gets leaked or compromised, and you can set filters to ignore future mail to that particular tagged address.
Yahoo offers up to 500 unique addresses per account. Initially this was a service provided by OtherInbox, now owned by Return Path, but it’s not clear if that’s still the case.
Spamgourmet has been offering disposable addresses since 2000. Their system has a built in limit on the number of emails a particular email will receive, which can help control the incoming volume.
Spamex is another provider of disposable addresses that’s been around for years and is providing services that allow recipients to control their incoming mail.
New on the scene is MeAndMyID.com who popped up in the comments here today. They are offering disposable addresses, free for a lifetime, if you sign up soon.
There are also the “short term” or “open inbox” disposable addresses like Malinator or 10 Minute Mail
I find disposable addresses invaluable for sorting through the mail coming into my account. A bank email to an address I didn’t give the bank? It’s a phish. A pizza hut email to an untagged address? Not real. Target emails to an address only given to Amazon? Amazon is selling or giving addresses away in violation of their privacy policy. Unexpected email from a vendor, but to a tagged address? Time to unsubscribe as I’ve lived this long without their mail.

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