Kumagai Gumi Group
alphvThis record tracks a ransomware attack claimed by the alphv group against Kumagai Gumi Group. It collects the publicly disclosed attack details — sector, location and timeline — as published on the operator's leak site and indexed by Breach House.
Window Zero
EXPOSURE GAPWindow Zero is the time the breach stayed in the open before anyone said so — the gap between when the attack was first discovered on the operator's leak site (t1) and when it was publicly disclosed (t2). The wider this window, the longer victims, staff and customers were exposed with no warning.
Attack Summary
Kumagai Gumi Co., Ltd. is a Japanese construction company founded in Fukui, Fukui Prefecture, Japan. The company still has registered headquartersin Fukui, but the actual head office is located in Shinjuku, Tokyo
Leak Screenshots
SAMPLEProof-of-breach screenshots the operator posted from the stolen data. Previews are redacted and locked — the originals are available on HaveIBeenRansom.