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

File encryption patterns

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

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
notes/READ_IT.txt
Location: Desktop

Technical indicators

Associated executable files

The following executable files are associated with First ransomware:

About this analysis

This First 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 First.

Last updated: December 30, 2025

Detection coverage

Elastio detects First inside your data and backups.

The Hunt Engine uses Deep File Inspection to identify First 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 →
What is First Ransomware? | Elastio