Ransomware Research

Proton Ransomware

Proton is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on March 1, 2023, this ransomware has been actively targeting systems worldwide.

Quick facts

Ransomware Family
Proton
First Seen
March 1, 2023

How Proton ransomware works

File encryption patterns

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

Extensions added after encryption
.kigatsu.Proton

Ransom note and payment demands

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

fileREADME.txt
notes/README.txt
Location: EveryFolder
file/^#[A-F0-9]{16}\.txt\b/
notes/#31F0982406032BE3.txt
Location: EveryFolder

Technical indicators

Associated executable files

The following executable files are associated with Proton ransomware:

About this analysis

This Proton 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 Proton.

Last updated: December 30, 2025

Detection coverage

Elastio detects Proton inside your data and backups.

The Hunt Engine uses Deep File Inspection to identify Proton 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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