Malware-less email attacks spike on Thursdays, says FireEye

FireEye has released the results of its Email Threat Report.

The study found that less than a third (32 percent) of email traffic seen in the first half of 2018 was considered ‘clean’ and actually delivered to an inbox. The report also found that 1 in every 101 emails had malicious intent. When compared to the previous six-month period, the changes in both these numbers depict that the email landscape continues to see an increase in email-based threats.

“Not only is email the most pervasive form of communication, it is also the most popular vector for cyber-attacks. This makes email the biggest vulnerability for every organisation,” said Ken Bagnall, vice president of email security at FireEye.

“From malware to malware-less attacks including impersonation attacks like CEO fraud, a single malicious email can cause significant brand damage and financial losses. By choosing an email security solution with features based on real-time knowledge gained from the frontlines, and by teaching users to always ensure they are communicating with who they think they are, organisations can better defend against attacks.”

With email security solutions focused on detecting malware, cybercriminals are now adapting their attacks, exposing organisations to malware-less assaults such as CEO fraud. In fact, the majority of attacks blocked (90 percent) during analysis were malware-less, with phishing attacks alone making up 81 percent of the blocked malware-less emails, almost doubling from January to June 2018. Data also indicates that phishing attacks will continue to rise, while impersonation attacks (which were at 19 percent) remain relatively proportional to the total number of attacks seen. With it only taking one email to potentially impact an entire organisation, the protection of this data must be taken seriously.

While the overall number of attacks stayed fairly consistent each month during the evaluated six-month period, a few notable trends stuck out relative to when and how attackers struck:

• Relative to malware-based attacks, Mondays and Wednesdays were most common
• Malware-less attacks were most likely to occur on a Thursday including domain name spoofing and attacks using a spoofed friendly user name, with the exception of newly existing domains which peaked on Wednesdays instead
• Impersonation attacks were most likely to fall on a Friday
• When it comes to the weekend, malware-less attacks continued to be more prevalent than malware-based attacks, with domain name spoofing attacks and newly existing domains being the most likely among them