This record tracks a ransomware attack claimed by the
medusa group against
Sermo. 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.
-44days
t1 · Published
t2 · Disclosed
Business Category
Healthcare / Pharma
Disclosed / Notified
May 19, 2025
Attack Summary
Sermo is an exclusive online community for licensed physicians, offering a platform for peer-to-peer collaboration, medical crowdsourcing, and real-time discussion of clinical cases. Sermo provides healthcare professionals with tools to connect globally, share insights, and improve patient care through collective knowledge.
Sermo's corporate office is located at 3 Times Square, 12th Floor, New York, NY 10036, United States, and has 450+ employees.
Leak Screenshots
SAMPLE
Proof-of-breach screenshots the operator posted from the stolen data. Previews are
redacted and locked — the originals are available on HaveIBeenRansom.
Dark Web Exposure
Findings for sermo.com
— indexed by HaveIBeenRansom.
767
found in Infostealer logs
1,607+
found in Traditional breaches
121+
found in Ransomware leaks
pureincubation-com.7z.001
Database World ROC · breach
••• emails
limeleads_breach.7z
TheUnderground - Reborn · breach
••• emails
Apollo.io DB 816millions.rar
Database World ROC · breach
••• emails
VerificationsIO_BF.7z.011
Kedr | Forum · breach
••• emails
SevenRooms_BF.7z
B F R e p o V 3 F i l e s · breach
••• emails
Televerde
play · ransomware
••• emails
@BreachedData1 LinkedIn 2021-23 Cleaned.7z.001
Database World ROC · breach
••• emails
linkedIN_2.7z.001
Database World ROC · breach
••• emails
+ 17 more leak sources locked
Leak volumes are locked
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Legal Disclaimer:
This ransomware victim record reflects information published on the operator's leak site.
Breach.house does not acquire, download, host, access or redistribute unlawfully obtained data. It indexes only publicly visible information posted by ransomware, breach and infostealer operators and open web sources, without accessing the underlying stolen content. The service supports public awareness, legitimate research and cyber-resilience.