Ransomware Research
BuLock Ransomware
BuLock is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on December 1, 2023, this ransomware has been actively targeting systems worldwide.
Quick Facts
- Ransomware Family
- BuLock
- First Seen
- December 1, 2023
How BuLock Ransomware Works
File Encryption Patterns
BuLock modifies encrypted files using specific patterns to mark them as encrypted:
File extensions added after encryption:
..bulock16Ransom Note and Payment Demands
After encrypting files, BuLock displays ransom notes demanding payment for file recovery:
HOW_TO_BACK_FILES.htmlRansom message:
notes/HOW_TO_BACK_FILES.html
Note locations:
EveryFolderTechnical Indicators
Associated Executable Files
The following executable files are associated with BuLock ransomware:
svhost.exe
Elastio Can Help You
Don't let BuLock ransomware take over your data
Elastio provides advanced ransomware protection and recovery solutions to keep your organization safe.
About This Analysis
This BuLock 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 BuLock.
Last updated: July 30, 2025