Ransomware Research

Locky Ransomware

Locky 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
Locky
First Seen
March 1, 2016

How Locky Ransomware Works

Targeted Files

Requires C&C to send and receive keys https://www.hybrid-analysis.com/sample/abdbc74907d7670a65b5a4cc8c08da751cc837a11d1abb43e3ddaa932bdbf60c?environmentId=4 https://unit42.paloaltonetworks.com/locky-new-ransomware-mimics-dridex-style-distribution/ https://forums.spybot.info/showthread.php?23632-SPAM-frauds-fakes-and-other-MALWARE-deliveries/page91 https://www.hybrid-analysis.com/sample/02b00f7615e1fd9091d947dad00dfe60528d9015b694374df2b5525ea6dd1301/56c477ddaac2eded037b23c9 https://www.bitsight.com/blog/locky-ransomware-metrics-and-protection Renames files by pattern -> DF383WRI-4T71-8KQP-88A0-028E2704F2E2.zzzzz https://www.bleepingcomputer.com/news/security/locky-ransomware-switches-to-thor-extension-after-being-a-bad-malware/ 5eced4c6bdb467d774eb3100a16a0ba0e85b1763e968ab4adcae5202c833beb0 -> rundll32 q.dll,EnhancedStoragePasswordConfig 147 https://malwarebreakdown.wordpress.com/2016/10/30/malspam-leads-to-locky-shit-linuxsucks-php/ b1c35b291a296b948758729f9fc775504ec764098dbc5c2e02796ee4ab174e0e -> WSH downloader ff4a021e6175e5f2c0a666270081d74991c69e651c249a6fdf82a004dd9215e5 -> kokoko

File Encryption Patterns

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

File extensions added after encryption:

..locky..loptr..thor..zzzzz..shit..lukitus..aesir

Ransom Note and Payment Demands

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

file/^loptr-\w{4}\.htm$/
file/^lukitus-\w{4}\.htm$/

Ransom message:

notes/lukitus-1df8.htm

Note locations:

EveryFolder
file/^.\d{1,3}-INSTRUCTION\.html$/

Ransom message:

notes/_180-INSTRUCTION.html

Note locations:

EveryFolder
file/^_\d_WHAT_is\.html$/

Ransom message:

notes/_0_WHAT_is.html

Note locations:

EveryFolder
file_Locky_recover_instructions.txt

Ransom message:

notes/_Locky_recover_instructions.txt

Note locations:

EveryFolder
screenshot

Ransom message:

notes/_Locky_recover_instructions.bmp

Note locations:

Desktop

Technical Indicators

Associated Executable Files

The following executable files are associated with Locky ransomware:

  • 20160301_b9fabd8fb7ec620295c232fa978b88f8.js
  • myfile.js
  • report.226915422.js
  • 8.png
  • 5.exe
  • content
  • 61f87e94f[1].png
  • a1.exe
  • 123.exe
  • Danger.exe
  • 793322-1-5e8b9_svchost.exe
  • svchost.exe
  • eiasus.exe

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About This Analysis

This Locky ransomware analysis is part of Elastio's comprehensive ransomware detection database. Elastio provides advanced ransomware protection and recovery solutions, helping organizations defend against and recover from ransomware attacks like Locky.

Last updated: September 30, 2025

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