The North Korean hacking group Kimsuky has been observed in recent attacks employing a custom-built RDP Wrapper and proxy tools to directly access infected machines. A new report by AhnLab's ASEC team details additional malware used by Kimsuky in these attacks, highlighting the group's intensified use of modified tools for unauthorized system access. This cyber espionage campaign begins with spear-phishing tactics, distributing malicious shortcut files disguised as legitimate documents to initiate the infection chain.
These files, often disguised as PDFs or Office documents, execute commands via PowerShell or Mshta to download malware such as PebbleDash and the custom RDP Wrapper, enabling remote control of compromised systems. Kimsuky's custom RDP Wrapper, a modified version of an open-source utility, includes export functions designed to evade detection by security software, facilitating stealthy remote access. In environments where direct RDP access is restricted, Kimsuky deploys proxy malware to bypass network barriers, maintaining persistent access and employing keyloggers and information-stealing malware to exfiltrate sensitive data.