North Korea-linked hacking group APT37 is using malicious JPEG image files to deploy advanced malware on Windows systems, according to Genians Security Centre. The new campaign showcases a more evasive version of RoKRAT malware, which hides payloads in image files through steganography.

These attacks rely on large Windows shortcut files embedded in email attachments or cloud storage links, enticing users with decoy documents while executing hidden code. Once activated, the malware launches scripts to decrypt shellcode and inject it into trusted apps like MS Paint and Notepad.

This fileless strategy makes detection difficult, avoiding traditional antivirus tools by leaving minimal traces. The malware also exfiltrates data through legitimate cloud services, complicating efforts to trace and block the threat.

Researchers stress the urgency for organisations to adopt cybersecurity measures, behavioural monitoring, robust end point management, and ongoing user education. Defenders must prioritise proactive strategies to protect critical systems as threat actors evolve.