A common misconception in security is that business email compromise (BEC) attacks most frequently target corporate leaders, specifically CEOs and CFOs.
Not the case, according to a new study of 3,000 BEC attacks analyzed by the Barracuda Sentinel Team. These threats, which have been responsible for billions of dollars in fraud losses over the past two years, are slipping past security tools as attackers learn which tactics work best.
Earlier this summer, the FBI reported BEC scams have caused more than $12 billion in domestic and international loss between October 2013 and May 2018. And the threat is growing: between December 2016 and May 2018, there was a 136% increase in reported global exposed losses.
While their techniques may be shifting, BEC attackers' primary motivation of financial gain remains the same. Barracuda found 46.9% of attacks were created to facilitate a wire transfer; in comparison, less than 1% aim to steal personally identifiable information (PII).
The small percentage of attacks targeting PII are focused on industries like healthcare and education, where organizations have vast stores of user data, explains Asaf Cidon, Barracuda's vice president of email security. Even in these incidents, the ultimate goal is financial gain: actors who steal users' personal data can turn around and sell it on the Dark Web.
But harvesting and selling PII is a more arduous process than getting an employee to wire funds straight into an attacker-controlled account. Cybercriminals want easy access to funds and, as researchers learned, they're increasingly proficient at getting targets to do their bidding.
Malicious Emails: No Links, No Problem
There are a few ways to go about deceiving employees into sending money. Some threat actors send "urgent" requests for specific amounts, assuming the employee will act immediately. Others try to build rapport with their targets before requesting the money transfer.
An important finding – the most significant, says Cidon – is fewer of these attacks include malicious links, which are often caught by security filters. Only 40% of BEC messages include links, while 60% do not, instead relying on social engineering techniques to be successful.
"What attackers realize is there's actually a lot of harm you can do in sending an email without any links," Cidon explains, adding most plaintext BEC emails request wire transfers. "They can probably do more damage through impersonation than by using phishing as the main hook."
Chris Hadnagy, founder and CEO at Social-Engineer, Inc., says he has noticed attackers get craftier as security technology improves and employees become more security-savvy. However, improved hardware and software has lulled companies into a false sense of security. They think they're safe with strong firewalls and IPS, but attackers are changing the game.
He explains the rise of combination attacks in which threat actors will send a plaintext email, sans links, in which they claim to have authority and request a wire transfer. They'll follow this up with a phone call: "Hey, this is Paul, I just sent an email … can you make that happen?"
"The combination of a vishing call with a phishing attack tends to help people believe and trust the attacker more," Hadnagy continues. "The days of sending malware-laden PDFs are gone – that doesn't exist anymore."
Prime Targets Have Less Power
The most likely targets for BEC attacks have less power than people think, says Cidon, noting that this is "actually a really big misconception" in the enterprise. CEOs, CFOs, and other high-level executives are frequently impersonated by attackers, he continues, but they are less frequently hit than the employees who report to them in IT, sales, marketing, operations, etc.
CEOs make up 2.2% of attack recipients but 42.9% of those impersonated, Barracuda researchers found. CFOs made up 16.9% of recipients and 2.2% of those impersonated. Finance/HR made up 16.9% of targets, while "other" made up more than half of attack targets.
"[Attackers] are portraying someone in higher power, whether it's the CEO or their secretary, and they're attacking those who fear for their jobs from that department," Hadnagy explains. The CEO and CFO can question their motives and deny wire transfers. Employees in middle management or below will hesitate to question an authority who makes a request.
"The point is, the separation has to be far enough that the individual doesn't know everyone in that higher level personally," he continues. If an attacker claims to work with the CEO and demands an urgent wire transfer, a lower-level employee is more likely to comply.
Threat actors can often find the corporate hierarchy – and other information they need to launch a BEC attack – with a simple online search. Employees often put their phone numbers on LinkedIn or business cards; even if they don't, there's a good chance their colleagues will. It's not hard to call someone and ask for their coworker's phone number, he points out.
It's even easier to seek out an employee's email address. Once an actor knows the email format for a company ([email protected], for example), they can plug in the name of their desired target.