This record tracks a ransomware attack claimed by the
AiLock group against
Yaomasa. 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 GAP
Window 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.
23days open
t1 · Published
t2 · Pending
Business Category
Manufacturing / Engineering
Published
August 13, 2026
Leak Status
pending
checked 2026-09-05
Disclosed / Notified
Not disclosed yet
Attack Summary
Yaomasa is a Japanese supermarket chain founded in 1919 that offers fresh foods, general groceries, and daily necessities, while also operating TSUTAYA and BOOKOFF franchise stores as part of its cultural division.
Leak Screenshots
1 CAPTURED
Captured directly from the operator's leak site by our collector, last checked 2026-09-05. Verdict evidence: [H11] Date:Coming soon
Showing the latest capture only
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Dark Web Exposure
Findings for yaomasa.com
— indexed by HaveIBeenRansom.
0
found in Infostealer logs
10
found in Traditional breaches
0
found in Ransomware leaks
Cit0day [cit0day.in] breaches.csv
LKnet reserve chat · breach
••• emails
VerificationsIO_BF.7z.011
Kedr | Forum · breach
••• emails
2844Breaches_BF.7z
B F R e p o V 3 F i l e s · breach
••• emails
Collection_RF 1300 DB.zip
DBs Backup · breach
••• emails
Collection#3.zip
DBs w MTDT · breach
••• emails
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