Rook Ransomware
Rook is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on November 1, 2021, this ransomware has been actively targeting systems worldwide.
Quick facts
How Rook ransomware works
File encryption patterns
Rook modifies encrypted files using specific patterns to mark them as encrypted:
Ransom note and payment demands
After encrypting files, Rook displays ransom notes demanding payment for file recovery:
notes/HowToRestoreYourFiles.txt
Technical indicators
Associated executable files
The following executable files are associated with Rook ransomware:
- J4PAZ.exe
About this analysis
This Rook 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 Rook.
Last updated: December 30, 2025
Elastio detects Rook inside your data and backups.
The Hunt Engine uses Deep File Inspection to identify Rook 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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