Spam is still the number one choice for online criminals

“Email spam is once again the most popular choice for sending out malware,” said Päivi Tynninen, Threat Intelligence Researcher at F-Secure. “Of the spam samples we’ve seen over the spring of 2018, 46% are dating scams, 23% are emails with malicious attachments, and 31% contain links to malicious websites.”

Spam has been one of the main infection vectors for decades, Päivi noted. “During the past few years, it’s gained more popularity against other vectors, as systems are getting more secure against software exploits and vulnerabilities,” she said.

The technique still relies on spewing out massive numbers of emails in order to snare a tiny number of users. And criminals continually refine their tactics to deliver to better results.

“Spam is becoming an increasingly successful attack vector, with click rates rising from 13.4% in the second half of 2017 to 14.2% in 2018,” said Adam Sheehan, Behavioral Science Lead at MWR InfoSecurity, the creators of phishd, a service that monitors and improves businesses susceptibility to phishing and other data-related attacks. MWR InfoSecurity was acquired by F-Secure in June of 2018.

While spam is a numbers game, MWR InfoSecurity’s effectiveness model has identified certain tactics that play on recipients’ psychology to make spam more potent: 

• The probability of a recipient opening an email increases 12% if the email claims to come from a known individual.
• Having a subject line free from errors improves spam’s success rate by 4.5%.
• A phishing email that states that its call to action is very urgent gets less traction than when the urgency is implied.

Criminals are not just relying on the content of spam to trick users. They are also using new methods to infect users who are wise to the dangers of clicking on unsolicited attachments.

“Rather than just using malicious attachments, the spam we’re seeing often features a URL that directs you to a harmless site, which then redirects you to site hosting malicious content. The extra hop is an analysis evasion method for keeping the malicious content hosted for as long as possible,” Päivi said.

“And when attachments are used, the criminals often attempt to avoid automatic analysis by asking the user to enter a password featured in the body of the email to open the file.”