F-Secure research shows that spam remains the most common method of spreading malicious URLs, scams and malware more than 40 years after the first email spam was sent.
“Email spam is once again the most popular choice for sending out malware,” says Päivi Tynninen, Threat Intelligence Researcher at F-Secure. “Of the spam samples we’ve seen over the spring of 2018, 46 percent are dating scams, 23 percent are emails with malicious attachments, and 31 percent contain links to malicious websites.”
Spam has been one of the main infection vectors for decades, Päivi notes. “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 says.
The technique still relies on sending 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 percent in the second half of 2017 to 14.2 percent in 2018,” says 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 by 12 percent 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 percent.
- 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 says. “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.”