Ransomware Research
Bonsoir Ransomware
Bonsoir is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on January 1, 2021, this ransomware has been actively targeting systems worldwide.
Quick Facts
- Ransomware Family
- Bonsoir
- First Seen
- January 1, 2021
How Bonsoir Ransomware Works
File Encryption Patterns
Bonsoir modifies encrypted files using specific patterns to mark them as encrypted:
File extensions added after encryption:
..bonsoirRansom Note and Payment Demands
After encrypting files, Bonsoir displays ransom notes demanding payment for file recovery:
HOW-RECOVER-MY-FILES.txtRansom message:
notes/HOW-RECOVER-MY-FILES.txt
Note locations:
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About This Analysis
This Bonsoir 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 Bonsoir.
Last updated: July 30, 2025