Most cybercriminals target people, not infrastructure: More than 99% of emails distributing malware from 2018 into 2019 required human interaction to click links, open documents, accept security warnings, or complete other tasks to effectively compromise an organization. Instead of targeting systems, criminals focus on people, their roles, and data they can access.
The data comes from Proofpoint, where for 18 months researchers observed attack trends to compile the “Human Factor 2019” report. What they found was an increasing sophistication and prevalence of social engineering across businesses as attackers shift from smash-and-grab ransomware campaigns to well-crafted business email compromise schemes and domain fraud.
“The vast majority of threats we see rely on some sort of human interaction,” says Chris Dawson, threat intelligence lead at Proofpoint. “We are still seeing, and occasionally will see, a spike in the use of a hardware or software vulnerability, but it still ends up being embedded in a malicious document.” Even with the use of an exploit and macros, human interaction is essential to follow links, open documents, accept security warnings, or complete other actions.
Generic email harvesting made up nearly 25% of all phishing schemes in 2018, Proofpoint reports. Credential collection remains a strong focus this year, with techniques pivoting to Microsoft Office 365 phishing schemes and impostor attacks. Cloud storage, DocuSign, and Microsoft cloud service phishing are this year’s hottest phishing lures, replacing last year’s trend of “Brain Food,” a botnet used to distribute diet-related spam to capture victims’ credit cards.
Attackers know companies are moving to the cloud, Dawson says, and if employees see something that looks familiar, they’ll click it, even if the sender is unfamiliar. People are used to seeing Office 365 and Dropbox links; the instinct to click precedes the instinct to think twice.
Impostor emails are shifting away from “Request” subject lines and are increasingly showing “Payment” or “Urgent” messages. Subject lines vary seasonally — W-2-related attacks were popular in late 2018 and early 2019 — and by industry. Education, for example, receives a disproportionate number of “Request” and “Greeting” emails, while attacks on engineering firms typically use “Urgent” and “Request” in the subject line. In keeping with business processes, most impostor emails are sent on Monday and trail off throughout the workweek.
Unlike broad campaigns that delivered ransomware in droves, today’s attackers leverage more-thoughtful attacks on a smaller scale. Their preference is for malware that can sit on a victim’s computer and remain there for a number of days or months without triggering any red flags. Many have taken to distributing sophisticated backdoors to collect data, Dawson explains.
“All of these things are designed to sit on a victim’s machine, collect data long term, and maybe do something later on,” he says. The industry is seeing a pattern of ransomware attacks in which it appears the organization had been compromised long before the infection began.
The Carbanak group, for example, uses lures and well-crafted file attachments to distribute multiple strains of malware, researchers report. One 2018 campaign included an email, with a file attached, that claimed to be protected with security technology. Instructions to “decrypt” the file enabled macros and installed the Griffon backdoor, which is often used in Carbanak campaigns.
Whose Inboxes Are at Risk?
Today’s campaigns are increasingly targeted; however, attackers are demonstrating variety in the types of people they target and how they craft their campaigns.
“The most attacked are people who are much more readily available,” says Dawson. This group often does not include C-level executives, who generally keep their online identities hidden. It does include salespeople, marketing teams, and human resources professionals, many of whom have publicly available emails. Of the “very attacked people,” or VAPs, identified, 36% of associated identities could be found online via corporate websites, social media, or other sites. In contrast, only 7% of executive email addresses could be found online, researchers report.
Crimes of opportunity, or emails to alias addresses like HR[@]company[.]com, are common. “It’s really quite difficult to secure a shared account,” Dawson says of alias email accounts.
Attackers are finding success in using more than five spoofed identities to target more than five individuals in each organization. “We see this pendulum swinging,” he adds of the switch from one-to-one attacks, to one-to-many attacks, to many-to-many attacks. Attackers may spoof the identities of several executives or senior managers while sending a malicious file to employees, or they could leverage a group of spoofed identities to ask the HR department for W-2 data.
Says Dawson: “They’re finding enough success with this technique that they are dramatically increasing the number of identities they use and the number of people they attack.”
Kelly Sheridan is the Staff Editor at Dark Reading, where she focuses on cybersecurity news and analysis. She is a business technology journalist who previously reported for InformationWeek, where she covered Microsoft, and Insurance & Technology, where she covered financial … View Full Bio