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
How BlackClaw ransomware works
File encryption patterns
BlackClaw modifies encrypted files using specific patterns to mark them as encrypted:
Ransom note and payment demands
After encrypting files, BlackClaw displays ransom notes demanding payment for file recovery:
notes/RECOVER YOUR FILES.hta
notes/RECOVER YOUR FILES.txt
About this analysis
This BlackClaw ransomware analysis is part of Elastio's comprehensive ransomware detection database. Elastio provides advanced ransomware protection and recovery, helping organizations defend against and recover from ransomware attacks like BlackClaw.
Last updated: December 30, 2025
Elastio detects BlackClaw inside your data and backups.
The Hunt Engine uses Deep File Inspection to identify BlackClaw across live data, replicated data, and backups. If this family is in your environment, Elastio finds it before encryption completes. Run a scan against your recovery points to confirm.
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