Ransomware Research

Skull Ransomware

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

Quick facts

Ransomware Family
Skull
First Seen
September 1, 2017

How Skull ransomware works

File encryption patterns

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

Extensions added after encryption
./\.[A-Za-z0-9]{6}$/

Ransom note and payment demands

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

fileHow_To_Decrypt_Your_Files.html
notes/How_To_Decrypt_Your_Files.html.txt

About this analysis

This Skull 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 Skull.

Last updated: December 30, 2025

Detection coverage

Elastio detects Skull inside your data and backups.

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