Ransomware Research

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

Ransomware Family
Rook
First Seen
November 1, 2021

How Rook ransomware works

File modification behavior

Rook updates file modification timestamps after encryption.

File encryption patterns

Rook modifies encrypted files using specific patterns to mark them as encrypted:

Extensions added after encryption
  • .Rook

Ransom note and payment demands

After encrypting files, Rook displays ransom notes demanding payment for file recovery:

fileHowToRestoreYourFiles.txt
notes/HowToRestoreYourFiles.txt

Location: EveryFolder

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: September 27, 2022

Detection coverage

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 hunt against your recovery points to confirm.