Ransomware Research
Kozy.Jozy Ransomware
Kozy.Jozy is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on June 1, 2016, this ransomware has been actively targeting systems worldwide.
Quick Facts
- Ransomware Family
- Kozy.Jozy
- First Seen
- June 1, 2016
How Kozy.Jozy Ransomware Works
File Encryption Patterns
Kozy.Jozy modifies encrypted files using specific patterns to mark them as encrypted:
File extensions added after encryption:
./\.[A-F0-9]{20}_\d{1,2}_[A-Z0-9]{4,5}\b/Ransom Note and Payment Demands
After encrypting files, Kozy.Jozy displays ransom notes demanding payment for file recovery:
Ransom message:
notes/note.txt
Ransom message:
notes/w.jpg
Note locations:
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About This Analysis
This Kozy.Jozy ransomware analysis is part of Elastio's comprehensive ransomware detection database. Elastio provides advanced ransomware protection and recovery solutions, helping organizations defend against and recover from ransomware attacks like Kozy.Jozy.
Last updated: July 30, 2025