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

Targeted Files

Full extension -> .[Kigatsu@tutanota.com][83E31018].kigatsu Encrypts some blocks of the files

File Encryption Patterns

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

File 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

Ransom message:

notes/README.txt

Note locations:

EveryFolder
file/^#[A-F0-9]{16}\.txt\b/

Ransom message:

notes/#31F0982406032BE3.txt

Note locations:

EveryFolder

Technical Indicators

Associated Executable Files

The following executable files are associated with Proton ransomware:

  • svchost.exe
  • AFC9674D2DFD9813.exe
  • x86.exe

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About This Analysis

This Proton ransomware analysis is part of Elastio's comprehensive ransomware detection database. Elastio provides advanced ransomware protection and recovery solutions, helping organizations defend against and recover from ransomware attacks like Proton.

Last updated: July 30, 2025

Proton Ransomware - Detectable by Elastio