The North Korean hackers behind the ongoing Contagious Interview campaign have been observed launching a new JavaScript malware named OtterCookie.
The campaign includes social engineering techniques, with the hacker team frequently posing as recruiters to trick job seekers into downloading malware during an interview process. This entails sharing malware-laced files via GitHub or the official package registry, paving the way for the propagation of malware like BeaverTail and InvisibleFerret.
Palo Alto Networks Unit 42, which first detected the activity in November 2023, is tracking the cluster as CL-STA-0240. In September 2024, Singaporean cybersecurity company Group-IB disclosed the deployment of an upgraded version of BeaverTail that employs a modular approach, delegating its information-stealing capability to a collection of Python scripts known as CivetQ.
According to the latest findings from Japanese cybersecurity company NTT Security Holdings, the JavaScript malware that launches BeaverTail is also designed to fetch and execute OtterCookie.
The new malware is said to have been launched in September 2024, with a new variant identified in the wild last month. OtterCookie, upon running, establishes connections with a command-and-control (C2) server using the Socket.IO JavaScript library, and awaits further instructions. It is intended to execute shell commands that facilitate data theft, including files, clipboard items, and cryptocurrency wallet keys.
The older OtterCookie variant discovered in September is functionally identical, but with a slight implementation difference: the cryptocurrency wallet key theft capability is directly incorporated into the malware, rather than a remote shell command. The discovery indicates that attackers are actively updating their tools while leaving the infection chain mostly intact, highlighting the campaign's efficacy.
This comes as South Korea's Ministry of Foreign Affairs (MoFA) sanctioned 15 individuals and one organisation in connection with a fraudulent IT worker program engineered by North Korea to establish a regular source of funds. These funds are funnelled to North Korea, often through data theft and other illegal means.
Kim Ryu Song, one of the 15 sanctioned individuals, was also charged by the U.S. Department of Justice (DoJ) earlier this month for allegedly participating in a long-running conspiracy to violate sanctions and commit wire fraud, money laundering, and identity theft by illegally seeking employment in U.S. companies and non-profit organisations.
