BLACK HAT EUROPE 2018 - London - Call it karma or just poor OpSec, but a prolific global cybercrime organization recently blew its cover after inadvertently targeting executives at a security firm.
The infamous Nigerian/UK group behind a rash of business email compromise (BEC) scams found itself on the other side of its own social-engineering scam when it posed as Agari CEO Ravi Kahtod in an Aug. 7 email sent to Raymond Lim, chief financial officer at Agari, an email security company.
Agari today disclosed details of both its unmasking of the group – which it has dubbed "London Blue" – as well as its inner workings. Security researchers at Agari flipped the equation on the attackers in an email exchange by posing as Lim's assistant and drawing out enough details to drill down into the particulars of the group as well as the physical location of its operators in London.
"Our email filter caught [the BEC email]," says Crane Hassold, senior director of threat research at Agari and a former FBI investigator. Hassold's team was ultimately able to extract the information, coupled with its own intel-gathering, to identify the two top execs of the gang, who live in and operate out of London.
The most striking finding, Hassold says, was that the operation used at least two legitimate lead-generation services that gave them more filtered intel for targeting C-level execs around the world, rather than having to cast a wide-net phishing campaign.
The lead-generation tools let them filter possible victims by role, location, and company size, for example, he says. The group purchased subscriptions to the tools, he says, which saved them time and labor. Among one list of 306 target victims that London Blue acquired in November 2017 was Agari CFO Lim, as well as California-based CFOs from a top private university, an enterprise data storage vendor, a well-known guitar manufacturer, casinos, hotels, and some small and midsize businesses.
Overall, the group has targeted some 50,000 CFOs worldwide across 82 countries, but mostly in the US, Agari found.
Like many of today's BEC emails, the attackers didn't bother to spoof the real email domain of the target; instead, they merely displayed the name "Ravi Khatod" in the email header. And there's no malware required with BEC: It's mainly a social engineering exploit.
Their initial email read:
Ray, we need to make a transfer today. Let me know if you can process now and I will send info. Thanks Ravi Khatod.
That's when the cat-and-mouse operation began. Agari researchers, posing as Lim's assistant Alicia, responded:
Ravi, Raymond is out this week and I will help you with the transfer. Would you please provide me with the transfer details? Also just a reminder, as you may know, all payments go out on Wednesday, which is tomorrow. So if you need to make another transfer or payment, please inform me so that I could take care of them together before tomorrow's cut-off passes. Best Regards, Alicia
The email exchange went from there, with Agari gathering more money-mule account information.
Hassold says the group's makeup of 20 to 25 individuals includes some 17 money mules spread around the US and Western Europe, and likely some members in Nigeria. At least three of the money mules have criminal records (including two sex offenders).
One transaction spotted by Agari was a $20,000 cashier's check obtained by a money mule from a large US bank. While the transaction initially triggered a potential fraud alert at a local branch, the money mule social-engineered the bank's fraud prevention group into approving it.
BEC as a Business
London Blue's operation includes the lead generation, lead assignments/sales, the BEC emails and social engineering, and then the movement of the pilfered funds. "This is organized like a business," Hassold says. "These cybercrime gangs are not just loosely affiliated low-level scammers."
BEC is becoming one of the most popular – and successful – cybercrime attacks. According to the FBI Internet Crime Complaint Center, BEC scams total some $12 billion in losses. Agari says a BEC scam typically nets four victims out of every 100 tries via email, and the average payment query is $35,000.
Agari has been working with law enforcement in the UK and US to identify the actors in London Blue, including the two top execs, who have not yet been apprehended. "If they get arrested, that will take this group down," Hassold says.
London blue is an "average" size BEC group, he says, among the 10 or more different Nigerian BEC groups Agari is tracking.
How did Agari convince the attackers they were falling for the scam? “They may have had a red flag during our interactions, but their financial motivation was so strong that it overrides [their hesitation]," he says.