This record tracks a ransomware attack claimed by the
clop group against
KIER.CO.UK. 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.
298days open
t1 · Published
t2 · Pending
Business Category
Construction / Real Estate
Published
November 07, 2025
Disclosed / Notified
Not disclosed yet
Attack Summary
[AI generated] KIER.CO.UK is a leading construction, property, and residential and infrastructure company in the UK. It operates across a range of sectors including defence, transportation, health, education, and utilities. The company offers services such as construction and civil engineering, maintenance and refurbishment. It is responsible for many landmark projects and also aims to make a positive difference in the areas it operates.
Leak Screenshots
SAMPLE
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What's In This Leak
Composition analysis from Have I Been Ransom · ransomware leak.
YES
Identity documents present
csv
115,545,344
records · 8,580 files
txt
466,943
records · 261 files
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records · ••••• files
Identity documents
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••% of records
Full composition is locked
Unlock the remaining 5 file type(s), the corporate vs personal email split and the identity-document analysis.
Dark Web Exposure
Findings for kier.co.uk
— indexed by HaveIBeenRansom.
134
found in Infostealer logs
2,970+
found in Traditional breaches
30+
found in Ransomware leaks
Apollo.io DB 816millions.rar
Database World ROC · breach
••• emails
pureincubation-com.7z.001
Database World ROC · breach
••• emails
@BreachedData1 LinkedIn 2021-23 Cleaned.7z.001
Database World ROC · breach
••• emails
SevenRooms_BF.7z
B F R e p o V 3 F i l e s · breach
••• emails
VerificationsIO_BF.7z.011
Kedr | Forum · breach
••• emails
TheUnderground - Reborn · breach
••• emails
B F R e p o V 3 F i l e s · breach
••• emails
+ 17 more leak sources locked
Leak volumes are locked
Sign in to reveal how many records each source exposed and the remaining 20 sources.
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