Ransomware Research
ByteLocker Ransomware
ByteLocker is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on February 1, 2018, this ransomware has been actively targeting systems worldwide. Security researchers also track this malware under the aliases: BytesLocker.
Quick Facts
- Ransomware Family
- ByteLocker
- First Seen
- February 1, 2018
- Known Aliases
- BytesLocker
How ByteLocker Ransomware Works
Targeted Files
.bytcrypttmp is a temporary extension during encryption process Config and list of files in registry -> HKEY_CURRENT_USER\SOFTWARE\ByteLocker
File Encryption Patterns
ByteLocker modifies encrypted files using specific patterns to mark them as encrypted:
File extensions added after encryption:
..bytcrypttmpRansom Note and Payment Demands
After encrypting files, ByteLocker displays ransom notes demanding payment for file recovery:
Ransom message:
notes/note.txt
Note locations:
LoginTechnical Indicators
Associated Executable Files
The following executable files are associated with ByteLocker ransomware:
ByteLocker.exeBytelocker.exe
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About This Analysis
This ByteLocker 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 ByteLocker.
Last updated: July 30, 2025