Threats Tagged 'apt43'

This analysis documents a third Vultr Seoul VPS (158.247.210.58) associated with Kimsuky operations, featuring over 60 domains across an 18-month period of systematic credential harvesting infrastructure. The actor demonstrates deliberate rotation through seven DDNS providers to evade blocklisting while maintaining the same backend VPS since at least September 2020. The domains systematically impersonate Naver, Korean National Tax Service (HomeTax), and government portals using prefixes like nid-user, n-store, nts-auth, and htax-login. Currently, 31 domains actively resolve while web ports remain closed, indicating a parked and ready operational posture. The infrastructure sits in AS20473 alongside two previously documented Vultr Seoul boxes, demonstrating the actor's clear preference for this provider and geographic proximity to South Korean targets.

On April 11, 2026, researchers analyzed a CHM file (api_reference.chm) tagged as Kimsuky that initiated a three-stage attack chain. The C2 server at check[.]nid-log[.]com had directory listing enabled, allowing recovery of complete source code for all payload stages: a 6,338-byte VBScript performing system reconnaissance and establishing persistence via scheduled task, a 449-byte VBScript bridge to PowerShell, and a 6,234-byte PowerShell keylogger with clipboard monitoring and timed exfiltration. The infrastructure included 79+ domains across 5 C2 IPs spanning Korean VPS providers. The server responded with "Million OK !!!!" signature, matching previously documented Kimsuky infrastructure while showing upgraded Apache/PHP stack. The operation targeted Korean Naver users through credential phishing and tax authority impersonation, with infrastructure linked to previously documented Kimsuky campaigns via shared DAOU Technology subnets.

This report details a cyber-espionage campaign attributed to Kimsuky, a North Korean APT group, targeting South Korean entities. The attack uses malicious Windows shortcut files as initial access, followed by obfuscated scripts and a sophisticated malware framework. The malware performs extensive system profiling, steals credentials and sensitive documents, monitors user activity, and exfiltrates data over standard web traffic. It establishes persistence, evades detection, and maintains communication with command-and-control infrastructure. The campaign demonstrates Kimsuky's evolution in stealth, modularity, and targeting precision, representing a serious espionage threat that requires advanced behavioral monitoring and network anomaly detection to combat.

MediumCampaignSouth KoreaGermanyFrance+3#data exfiltration#reflective dll injection#powershell