Ransomware Research

Locky-Osiris Ransomware

Locky-Osiris is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on December 1, 2016, this ransomware has been actively targeting systems worldwide.

Quick facts

Ransomware Family
Locky-Osiris
First Seen
December 1, 2016

How Locky-Osiris ransomware works

File encryption patterns

Locky-Osiris modifies encrypted files using specific patterns to mark them as encrypted:

Extensions added after encryption
.osiris

Ransom note and payment demands

After encrypting files, Locky-Osiris displays ransom notes demanding payment for file recovery:

fileDesktopOSIRIS.htm
notes/DesktopOSIRIS.htm
Location: UserProfile
file/^OSIRIS-[a-f0-9]{4}\.htm\b/
notes/OSIRIS-d004.htm
Location: EveryFolder
screenshot
notes/DesktopOSIRIS.bmp
Location: Desktop

Technical indicators

Associated executable files

The following executable files are associated with Locky-Osiris ransomware:

About this analysis

This Locky-Osiris 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 Locky-Osiris.

Last updated: December 30, 2025

Detection coverage

Elastio detects Locky-Osiris inside your data and backups.

The Hunt Engine uses Deep File Inspection to identify Locky-Osiris 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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