Ransomware Research
Jeffery Ransomware
Jeffery is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on April 1, 2025, this ransomware has been actively targeting systems worldwide.
Quick Facts
- Ransomware Family
- Jeffery
- First Seen
- April 1, 2025
How Jeffery Ransomware Works
File Encryption Patterns
Jeffery modifies encrypted files using specific patterns to mark them as encrypted:
File extensions added after encryption:
..JefferyRansom Note and Payment Demands
After encrypting files, Jeffery displays ransom notes demanding payment for file recovery:
JEFFERY_README.txtRansom message:
notes/JEFFERY_README.txt
Note locations:
DesktopRansom message:
notes/school-courtyard.jpg
Note locations:
DesktopTechnical Indicators
Associated Executable Files
The following executable files are associated with Jeffery ransomware:
School Homework.exe
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About This Analysis
This Jeffery 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 Jeffery.
Last updated: October 30, 2025
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