Ransomware Research

First Ransomware

First is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on January 1, 2017, this ransomware has been actively targeting systems worldwide.

Quick Facts

Ransomware Family
First
First Seen
January 1, 2017

How First Ransomware Works

Targeted Files

https://twitter.com/JaromirHorejsi/status/815949909648150528

File Encryption Patterns

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

File extensions added after encryption:

..locked..krzysioka

Ransom Note and Payment Demands

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

fileREAD_IT.txt

Ransom message:

notes/READ_IT.txt

Note locations:

Desktop

Technical Indicators

Associated Executable Files

The following executable files are associated with First ransomware:

  • firstransomware.exe

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About This Analysis

This First 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 First.

Last updated: July 30, 2025

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