Bitcoin Exchange Job Lure Traces to Hackers Tied to North Korea
Bitcoin-seeking hackers are using old-school tricks to socially engineer would-be cryptocurrency exchange executives, researchers warn.
An attack group tied to North Korea has “launched a malicious spear-phishing campaign using the lure of a job opening for the CFO role at a European-based cryptocurrency company,” researchers at Secureworks Counter Threat Unit warn in a report.
The CTU researchers refer to the group behind the attack as “Nickel Academy,” although it is perhaps better known as the Lazarus Group (see Kaspersky Links North Korean IP Address to Lazarus ).
The group has been tied to numerous attacks, including the attempted theft of nearly $1 billion from the central bank of Bangladesh’s New York Federal Reserve account, leading to $81 million being stolen; the WannaCry ransomware outbreak in May; as well as the use of cryptocurrency mining malware named Adylkuzz to attack the same flaw in Windows server block messaging that WannaCry also targeted (see Cybercriminals Go Cryptocurrency Crazy: 9 Factors).
Fake Job Lures
The CTU researchers say Lazarus has also been running a series of job lure phishing attacks since at least 2016, with the latest round being delivered around Oct. 25 of this year. They say the malicious code has “solid technical linkages” to attacks previously attributed to Lazarus (see Report: North Korea Seeks Bitcoins to Bypass Sanctions).
If recipients of the latest CFO job lure phishing emails open an attached Microsoft Word document, it triggers a pop-up message inviting them to enable editing functions. The CTU researchers say this is an attempt to enable macros in Word, so that a malicious macro hidden inside the document can execute. If it does, the macro creates a decoy document – the CFO job lure – as well as installs a first-stage remote access Trojan RAT in the background. Once the RAT is running on the victim’s PC, attackers can use it to install additional malware onto the system, such as keystroke loggers and password stealers.
The CTU researchers say the job listing appears to have been stolen from a legitimate CFO job listing posted to LinkedIn by a cryptocurrency firm in Asia. While the researchers say that Lazarus has done this previously, unusually in this case, some typographical errors in the original listing were expunged. The researchers add that this phishing campaign does not appear to target any specific firm or individual, but rather to be more broadly aimed.
“There are common elements in the macro and in the first-stage RAT used in this campaign with former campaigns,” the researchers write. The custom command-and-control network code that controls infected endpoints also includes components that were seen in previous attacks tied to Lazarus, they add.
Skyrocketing Interest in Bitcoins
The ease of hacking bitcoins, the pseudonymity it offers, as well as the skyrocketing value of the cryptocurrency has led many cybercrime groups to focus on bitcoin theft.
“There are at least four very advanced threat actor groups who have been attacking banks in recent years, and about a month ago, they just dropped their activities and moved over to bitcoin hacking,” Avivah Litan, vice president and distinguished analyst at Gartner Research, tells Information Security Media Group, citing information she’s received from threat intelligence researchers.
Security experts say those groups include hacking teams tied to Russian organized crime as well as North Korea, especially in light of sanctions being imposed on both countries. By some estimates, one-third of cash-strapped North Korea’s gross domestic product may come from hacking.
“It is a fact that North Korea has been attacking virtual currency exchanges,” Lee Dong-geun, a director with South Korea’s state-run Korea Internet and Security Agency, tells CNN. “We don’t know how much North Korea has stolen so far, but we do know that the police have confirmed the regime’s hacking attempts.”
Given bitcoin’s popularity with investors in the United States – among other countries – it might seem ironic that the majority of Americans don’t know the location of North Korea, according to Conrad Hackett, a senior demographer and associate director at Pew Research Center, a nonpartisan U.S. think tank in Washington.
Each dot is a US adult’s guess about the location of North Koreahttps://t.co/t8MJNNSiXF pic.twitter.com/LDaCvVRGFn
— Conrad Hackett (@conradhackett) December 18, 2017
But online attacks know no boundaries. And hack attempts need not be launched by nation states to be effective.
“We like worrying about nation-state attacks, like the Mirai botnet,” Brian Honan, head of cybersecurity firm BH Consulting in Dublin, tells ISMG. “When that came out, people said it was Iran or North Korea exercising their cyber weapons.”
But many of the Mirai botnet attacks seen to date were allegedly launched by the likes of U.S. college students and a man also accused of developing and selling RATs on cybercrime forums (see Mirai Malware Attacker Extradited From Germany to UK).
Essential Phishing Defenses
Regardless of who’s launching phishing campaigns or targeting individuals’ cryptocurrency holdings, the CTU researchers say the CFO job lure campaign is a reminder to all email users – and especially cryptocurrency firms – to take several security steps.
- Social engineering training: Train and remind employees to never open attachments or links from unknown sources, and to verify all apparently trusted senders’ identities before opening anything they have sent.
- Sandbox: Use anti-malware tools that will sandbox all email attachments and web links and attempt to assess whether or not they are malicious before allowing users to interact with them.
- Disable macros: By default, Microsoft Office disables all macro functionality. Leave it that way, security experts say.
- Two factors: Implement two-factor authentication on all key systems to help blunt successful phishing attacks that lead to credential theft.
and even if they do know the sender verify with the sender before opening.
While all users should keep those information security basics in mind, as bitcoin’s value continues to soar, it’s a sure bet that anyone who dabbles in cryptocurrency will be at increasing risk from attackers.