Ransomware incidents in Japan in the first half of 2026: Investigation of The Gentlemen’s infrastructure and evidence of Qilin's AI use

Ransomware incidents in Japan rose 4.7% year over year. The Gentlemen was the most active group, with leak-site listings more than doubling from January to July. Qilin ranked second and appeared to use AI, while SMEs with capital under JPY 1 billion represented 80% of victims.