Ransomware Research

Surprise Ransomware

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

Quick facts

Ransomware Family
Surprise
First Seen
March 1, 2016

How Surprise ransomware works

File encryption patterns

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

Extensions added after encryption
.surprise.tzu

Ransom note and payment demands

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

fileDECRYPTION_HOWTO.Notepad
notes/DECRYPTION_HOWTO.Notepad
Location: Desktop

About this analysis

This Surprise 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 Surprise.

Last updated: December 30, 2025

Detection coverage

Elastio detects Surprise inside your data and backups.

The Hunt Engine uses Deep File Inspection to identify Surprise 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 Surprise Ransomware? | Elastio