APT37, a DPRK-backed threat group, has launched a new campaign called Ruby Jumper, utilizing Windows shortcut files to initiate attacks with newly discovered tools. These tools include RESTLEAF, SNAKEDROPPER, THUMBSBD, and VIRUSTASK, which work together to deliver surveillance payloads like FOOTWINE and BLUELIGHT. The campaign leverages removable media to infect and communicate with air-gapped systems. Key features include the use of Ruby for shellcode-based payloads, abuse of cloud storage services for command and control, and sophisticated techniques for bypassing network isolation. The malware demonstrates advanced capabilities in system reconnaissance, data exfiltration, and persistent surveillance.