Ransomware Research

JOKER Ransomware

JOKER is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on July 1, 2024, this ransomware has been actively targeting systems worldwide.

Quick facts

Ransomware Family
JOKER
First Seen
July 1, 2024

How JOKER ransomware works

File encryption patterns

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

Extensions added after encryption
./\.[0-9a-z]{4}$/.encrypted

Ransom note and payment demands

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

fileread_it.txt
notes/read_it.txt
Location: EveryFolder
fileNOTE FROM THE HACKERS.txt
notes/NOTE FROM THE HACKERS.txt
Location: EveryFolder
screenshot
notes/ju3z51i4j.jpg
Location: Desktop
screenshot
notes/2k709lio6.jpg
Location: Desktop

Technical indicators

Associated executable files

The following executable files are associated with JOKER ransomware:

About this analysis

This JOKER 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 JOKER.

Last updated: December 30, 2025

Detection coverage

Elastio detects JOKER inside your data and backups.

The Hunt Engine uses Deep File Inspection to identify JOKER 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.

See How the Hunt Engine WorksRequest a Demo

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