Top website domains are vulnerable to email spoofing

A security firm looked at the email authentication systems of top websites

Don’t be surprised if you see spam coming from the top websites in the world. Lax security standards are allowing anyone to "spoof" emails from some of the most-visited domains, according to new research.

Email spoofing — a common tactic of spammers — basically involves forging the sender’s address. Messages can appear as if they came from Google, a bank, or a best friend, even though the email never came from the actual source. The spammer simply altered the email’s "from" address.

Authentication systems have stepped in to try and solve the problem. But many of the top website domains are failing to properly use them, opening the door for spoofing, according to Sweden-based Detectify, a security firm.

The company analyzed the top 500 websites ranked by Alexa and found that 276 of the domains are vulnerable as a result, it said in a blog post on Monday.

Of those vulnerable, 40 percent were news and media sites, and 16 percent were software-as-a-service sites, Detectify said in an email.

A common way these domains are trying to prevent email spoofing is through a validation system called Sender Policy Framework or SPF. It essentially creates a public record, telling the Internet which email servers are allowed to use the domain. Ideally, any messages impersonating the domain will be detected as spam and rejected before delivery.

In practice, however, the system can often come up short. The SPF will filter out spam emails best when on the so-called "hardfail" setting, but many website domains decide to implement the SPF at the "softfail" level. Although this will flag any forged emails as suspected spam, the messages will still be sent out to the recipient.

Companies in charge of the website domains do this to avoid losing legitimate emails that might be falsely flagged, said John Levine, a long-time email infrastructure consultant.

“There are a lot of ways to send mail legitimately, and SPF can only describe some of them,” he added.

Email providers such as Gmail can also skip marking any messages as spam, even if an SPF system softfail was used, Detectify said.

The 276 web domains found vulnerable were using no SPF system or had set their SPF system on softfail. Others had misconfigured their email validation systems to do nothing when detecting spam, Detectify said.

Companies in charge of these domains are either unaware of the problem, or assume they’re already protected, Detectify said. Enacting better email validation systems can also be complicated, and some companies don’t see it as a priority.

"Many people falsely think they’re protected using SPF only," Detectify added. The security firm is advising companies use a newer email validation system, called DMARC (Domain-based Message Authentication, Reporting & Conformance) to prevent the problem.

DMARC is gaining wider adoption in the IT industry, including from Yahoo and Google. The protocol is essentially designed to streamline the process of email spoofing detection, but still not everyone is using it.

Detectify’s research found that only 42 percent of the top 500 sites in the world use DMARC.

Although DMARC is "far from foolproof," the system has been effective in preventing email-based attacks, Levine said.

For instance, phishing attacks against Paypal users may have dropped as a result of email providers adopting DMARC, security firm Kaspersky Lab said in 2015.

Join the CSO newsletter!

Error: Please check your email address.

More about GoogleKasperskyYahoo

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Michael Kan

Latest Videos

  • 150x50

    CSO Webinar: Will your data protection strategy be enough when disaster strikes?

    Speakers: - Paul O’Connor, Engagement leader - Performance Audit Group, Victorian Auditor-General’s Office (VAGO) - Nigel Phair, Managing Director, Centre for Internet Safety - Joshua Stenhouse, Technical Evangelist, Zerto - Anthony Caruana, CSO MC & Moderator

    Play Video

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

More videos

Blog Posts

Market Place