In a joint effort, the National Cyber Security Centre (NCSC) and South Korea's National Intelligence Service (NIS) have issued a serious warning about the activities of the Lazarus hacking group, associated with North Korea. The group is exploiting a zero-day vulnerability found in the widely-used MagicLine4NX software, leading to a series of sophisticated supply-chain attacks affecting various entities globally.

The MagicLine4NX software, developed by Dream Security in South Korea, is a crucial joint certificate program for secure logins and digital transactions. Exploiting a vulnerability in this software, cyber actors gained unauthorized access to the intranets of targeted organizations, breaching security authentication systems in the process.

The joint advisory revealed, "Cyber actors utilized the software vulnerabilities to gain unauthorized access to the intranet of a target organization. They exploited the MagicLine4NX security authentication program for initial intrusion and a zero-day vulnerability in network-linked systems to move laterally, accessing sensitive information."

The intricate attack chain began with a watering hole attack, a tactic where hackers compromise websites frequented by specific users. In this case, state-sponsored hackers infiltrated a media outlet's website, embedding malicious scripts into an article. The attack specifically targeted visitors using certain IP ranges. When visitors employed the MagicLine4NX authentication software and accessed the compromised website, the embedded code executed, providing hackers with complete control over the system.

Subsequently, the attackers accessed an internet-side server from a network-connected PC, exploiting system vulnerabilities. They then spread the malicious code to a business-side server via a network-linked system's data synchronization function.

Despite security measures, the threat actors persisted in attempting to infiltrate business PCs with the aim of extracting sensitive information. The malware established a connection to two C2 servers—one serving as a gateway within the network-linked system and the other located externally on the internet. The report noted, "The malicious code attempted to move data from the internal server to the external server but was thwarted by the security policy. Had it succeeded, substantial internal network information might have been compromised."

The warning emphasized the severity of such attacks, citing previous supply chain intrusions by North Korea-linked APT groups. Notably, the Labyrinth Chollima APT targeted VoIP software maker 3CX, leading cybersecurity vendors to detect the popular software as malware. In a separate incident, Microsoft Threat Intelligence researchers exposed a supply chain attack by APT Diamond Sleet (ZINC), affecting over 100 devices across Japan, Taiwan, Canada, and the United States.

As cybersecurity agencies work to contain these threats, the increasing sophistication of these attacks underscores the urgent need for heightened vigilance and robust security measures against supply-chain vulnerabilities.