North Korea's constantly evolving Lazarus Group appears to have diversified into skimming online payment cards over the past year or so.
Sansec, a Netherlands-based security firm, says its researchers have found evidence tying the advanced persistent threat (APT) group to attacks on the websites of several large US retailers going back to at least May 2019. In each of the attacks, the threat actors planted malicious code for capturing payment card data entered into checkout pages by people paying for purchases on these sites.
In a report Monday, Sansec says it has so far not been able to determine how the attackers managed to breach these sites initially in order to plant the card-skimming code. But data from the attacks shows Lazarus Group members used the website of an Italian modeling agency, a vintage music store in Iran, a family-run bookstore in New Jersey, and other sites to funnel stolen payment card data to Dark Web market places. The sites — which were running WordPress — were previously compromised and repurposed to distribute the stolen assets, Sansec says in its report.
"They used these compromised WordPress sites as exfiltration proxies," says Willem de Groot, a security researcher at Sansec. "During store purchases, card data was logged and sent to these exfiltration nodes." The purpose of these proxies is to hide the true destination of the stolen assets, he notes.
In its report, Sansec says it has identified "multiple, independent links between recent skimming activity and previously documented North Korean hacking operations." Among the pieces of evidence are several IP addresses and domains that have been previously associated with the Lazarus Group.
The Sansec report identified jewelry and fashion accessories firm Claire's as one of the organizations impacted in the attacks. But it did not offer any information on other victims or the volume of card data that Lazarus Group might have stolen so far. According to de Groot, the intelligence Sansec has gathered suggests the APT group infiltrated at least a "few dozen stores with several large US retailers among them."
In attacks involving some of the larger brands, Lazarus Group members used dedicated exfiltration domains — rather than the compromised WordPress websites — to funnel stolen card data to underground markets, de Groot says.
"It is clear that a lot of preparation and effort was invested in setting up these later campaigns," he says. "This contrasts with Magecart activity over the last few years, which was largely opportunistic."
Constantly Evolving Tactics
The Lazarus Group (aka Hidden Cobra) is a well-known APT group that the US government and others have described as acting on behalf of North Korea's (DPRK) government. In recent years, the group has been associated with a string of high-profile attacks, including one on Sony Pictures in 2014, the WannaCry ransomware attacks, and another on the Bank of Bangladesh, which netted it some $81 million. In recent years the group has also been associated with numerous cryptocurrency-mining campaigns.
"Over the years DPRK actors have demonstrated their ability to use instruments and techniques that are not usually related to APT operations," says Jim Walter, threat researcher at SentinelOne. As examples, he points to Lazarus Group's cryptomining and its adoption of commodity malware and other common off the shelf tools.
"In SentinelLabs, we revealed in the past how DPRK actors are working with commercial cybercrime tools, like TrickBot Anchor Project," he says.
Many believe that Lazarus Group's financially motivated attacks are designed to generate money for the sanction-hit North Korean government's nuclear program.
"Traditionally, seeing a state-sponsored group carry out a card-skimming campaign might seem curious, especially if it was a wealthier nation," says Hank Schless, senior manager of security solutions at Lookout. "However, North Korea is so heavily sanctioned and struggles economically, so it will clearly use whatever tactics it can to get access to funds."
Brandon Hoffman, CISO, and head of security strategy at Netenrich, says the Lazarus Group's move further into the realm of cybercrime is no surprise given its past activities.
"From their perspective, if they have the tools and skills to perform advanced persistent threat activity, why wouldn't they use it to fill the coffers as well?" he says.