Ransomware Research
BlackClaw Ransomware
BlackClaw is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on May 1, 2020, this ransomware has been actively targeting systems worldwide. Security researchers also track this malware under the aliases: Black Claw.
Quick Facts
- Ransomware Family
- BlackClaw
- First Seen
- May 1, 2020
- Known Aliases
- Black Claw
How BlackClaw Ransomware Works
Targeted Files
Encrypts first 0x100200 bytes
File Encryption Patterns
BlackClaw modifies encrypted files using specific patterns to mark them as encrypted:
File extensions added after encryption:
..bclaw..apocalypseRansom Note and Payment Demands
After encrypting files, BlackClaw displays ransom notes demanding payment for file recovery:
RECOVER YOUR FILES.htaRansom message:
notes/RECOVER YOUR FILES.hta
Note locations:
EveryFolderRECOVER YOUR FILES.txtRansom message:
notes/RECOVER YOUR FILES.txt
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About This Analysis
This BlackClaw 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 BlackClaw.
Last updated: July 30, 2025