Ransomware Research

Louis Ransomware

Louis is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on March 1, 2025, this ransomware has been actively targeting systems worldwide.

Quick facts

Ransomware Family
Louis
First Seen
March 1, 2025

How Louis ransomware works

File encryption patterns

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

Extensions added after encryption
.Louis

Ransom note and payment demands

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

fileLouis_Help.txt
notes/Louis_Help.txt
Location: EveryFolder
screenshot
notes/1.png
Location: Desktop

Technical indicators

Associated executable files

The following executable files are associated with Louis ransomware:

About this analysis

This Louis 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 Louis.

Last updated: December 30, 2025

Detection coverage

Elastio detects Louis inside your data and backups.

The Hunt Engine uses Deep File Inspection to identify Louis 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

Recent ransomware

Explore other threats in our database

Wxlongda2025VeilCrypt2025TitanLabooboo2025SolidBit2022SnapHackLocker2024PySystemUpdate2025PySimCrypt2025Monkey2025Lol2025HWID2025
View all ransomware →