Ransomware Research

BigLock Ransomware

BigLock is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on May 1, 2020, this ransomware has been actively targeting systems worldwide. Security researchers also track this malware under the aliases: CoronaLock, Corona-lock, CoronaLocker.

Quick facts

Ransomware Family
BigLock
First Seen
May 1, 2020
Known Aliases
CoronaLockCorona-lockCoronaLocker

How BigLock ransomware works

File encryption patterns

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

Extensions added after encryption
.biglock.corona-lock.pandemic.systems32x.nermer.t1000.t800

Ransom note and payment demands

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

fileREADME_LOCK.TXT
notes/README_LOCK.TXT
Location: Desktop
filePROTECT.txt
file@_FILES_WERE_ENCRYPTED_@.TXT
notes/@_FILES_WERE_ENCRYPTED_@.TXT
Location: EveryFolder
file@_HOW_TO_DECRYPT_FILES_@.TXT
notes/@_HOW_TO_DECRYPT_FILES_@.TXT
Location: EveryFolder
file@_HOW_TO_PAY_THE_RANSOM_@.TXT
notes/@_HOW_TO_PAY_THE_RANSOM_@.TXT
Location: EveryFolder
filePROTECT_INFO.TXT
notes/PROTECT_INFO.TXT
Location: Desktop
fileCRYPTiNFO.TXT
notes/CRYPTiNFO.TXT
Location: Desktop
file!!!HOW_TO_DECRYPT!!!.txt

Technical indicators

Associated executable files

The following executable files are associated with BigLock ransomware:

About this analysis

This BigLock 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 BigLock.

Last updated: December 30, 2025

Detection coverage

Elastio detects BigLock inside your data and backups.

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