Ransomware Research

3301 Ransomware

3301 is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on August 1, 2017, this ransomware has been actively targeting systems worldwide.

Quick facts

Ransomware Family
3301
First Seen
August 1, 2017

How 3301 ransomware works

File encryption patterns

3301 modifies encrypted files using specific patterns to mark them as encrypted:

Extensions added after encryption
.3301

Ransom note and payment demands

After encrypting files, 3301 displays ransom notes demanding payment for file recovery:

fileDECRYPT_MY_FILES.HTML
notes/DECRYPT_MY_FILES.HTML
Location: EveryFolder
screenshot
notes/wl.bmp
Location: Desktop

Technical indicators

Associated executable files

The following executable files are associated with 3301 ransomware:

About this analysis

This 3301 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 3301.

Last updated: December 30, 2025

Detection coverage

Elastio detects 3301 inside your data and backups.

The Hunt Engine uses Deep File Inspection to identify 3301 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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