October 22, 2015 By Douglas Bonderud 2 min read

Email spam is a problem. While overall numbers have been dropping, Securelist reported that in Q2 2015, more than 50 percent of all email traffic came from spammers. What’s more, malicious actors have changed tactics to focus on the next generation of tech-savvy consumers: Rather than looking for bank details or personal information, new phishing emails target social connections while malware-carrying attachments are camouflaged to look like antivirus or OS updates. But advancements in detection, particularly the DMARC protocol, have the potential to send spam packing.

Spam Has an Easy Way In

As noted by CSO Online, one of the easiest ways for attackers to convince victims their emails are genuine is by spoofing the sender address. If users believe the message really is from Microsoft, their antivirus company or a trusted friend, they’re far more likely to open, read and even download an attachment. And once attackers have access to a user’s system, they can both send emails from an infected account and use contact list data to spoof a whole new set of addresses.

While early spam-detection efforts focused on message content or relied on users to self-identify bad emails, attackers have quickly graduated to a new level of sophistication by lifting company logos, including working phone numbers and generally brushing up on their grammar. The result? Fake and legitimate messages look and sound almost identical.

DMARC-ation

Fortunately, Google and Yahoo have a plan: the Domain-based Message Authentication, Reporting and Conformance (DMARC) protocol. According to Threatpost, DMARC takes a hard line against email spoofing by checking all messages against both Domain Keys Identified Mail (DKIM) and Sender Policy Framework (SPF) validation systems.

DKIM relies on a wrapped cryptographic signature to verify the sender domain, while SPF lets senders specify which hosts are able to carry their messages, making spoofed emails easy to identify. In combination, the DMARC protocol makes it almost impossible for spam to slip through — if both the DKIM and SPF checks aren’t successful, the message is quarantined.

Under the new DMARC system, senders can provide information to recipients on what they can do if legitimate emails aren’t getting through, while recipients can send feedback to senders letting them know why their messages were flagged. Yahoo is set to implement the protocol for its ymail.com and rocketmail.com services by Nov. 2, 2015, while Google says it’s moving to a “strict” DMARC policy by June of next year.

While it’s unlikely that even DMARC can completely eliminate spam, it’s a step in the right direction; make spoofing messages hard enough for attackers and they’ll start looking somewhere else. Even with DMARC up and running, however, users can’t get overconfident: Better safe than spoofed.

More from

When ransomware kills: Attacks on healthcare facilities

4 min read - As ransomware attacks continue to escalate, their toll is often measured in data loss and financial strain. But what about the loss of human life? Nowhere is the ransomware threat more acute than in the healthcare sector, where patients’ lives are literally on the line.Since 2015, there has been a staggering increase in ransomware attacks on healthcare facilities. And the impacts are severe: Diverted emergency services, delayed critical treatments and even fatalities. Meanwhile, the pledge some ransomware groups made during…

AI and cloud vulnerabilities aren’t the only threats facing CISOs today

6 min read - With cloud infrastructure and, more recently, artificial intelligence (AI) systems becoming prime targets for attackers, security leaders are laser-focused on defending these high-profile areas. They’re right to do so, too, as cyber criminals turn to new and emerging technologies to launch and scale ever more sophisticated attacks.However, this heightened attention to emerging threats makes it easy to overlook traditional attack vectors, such as human-driven social engineering and vulnerabilities in physical security.As adversaries exploit an ever-wider range of potential entry points…

4 trends in software supply chain security

4 min read - Some of the biggest and most infamous cyberattacks of the past decade were caused by a security breakdown in the software supply chain. SolarWinds was probably the most well-known, but it was not alone. Incidents against companies like Equifax and tools like MOVEit also wreaked havoc for organizations and customers whose sensitive information was compromised.Expect to see more software supply chain attacks moving forward. According to ReversingLabs' The State of Software Supply Chain Security 2024 study, attacks against the software…

Topic updates

Get email updates and stay ahead of the latest threats to the security landscape, thought leadership and research.
Subscribe today