Icefog is an espionage campaign and associated backdoor set, also known as Fucobha, that had operated since at least 2011 when it was documented in 2013. It primarily targeted organizations in Japan and South Korea, including government bodies, military contractors, shipbuilding and maritime groups, telecommunications operators, industrial and high-technology companies, and media. The attackers used spear-phishing and exploits delivered through Microsoft Office, Java, Help, and Hangul documents, then interactively controlled compromised hosts with Icefog backdoors and lateral-movement tools; attribution was investigated but not presented as conclusive.