Remove MedusaLocker ransomware from your operating system

Also Known As: MedusaLocker virus
Distribution: Moderate
Damage level: Severe

MedusaLocker ransomware removal instructions

What is MedusaLocker?

Discovered by MalwareHunterTeam, MedusaLocker is malicious software, which is classified as ransomware. It operates by encrypting files and keeping them inaccessible until a ransom is paid (i.e. the decryption software/tool is purchased). During the encryption process, all files are renamed with the ".encrypted" extension. For example, "1.jpg" becomes "1.jpg.encrypted". Once data is encrypted, MedusaLocker stores an HTML file ("HOW_TO_RECOVER_DATA.html") containing a ransom message on the victim's desktop. Other variants of this ransomware use the ".bomber", ".boroff", ".breakingbad", ".locker16", ".newlock", ".nlocker", ".skynet", ".deadfiles", ".abstergo", ".himynameisransom", ".ReadInstructions", ".EG", ".decrypme", ".ReadTheInstructions", and ".READINSTRUCTIONS" extensions for encrypted files.

The ransom message states that the users' files have been encrypted and, to recover them, they must purchase a unique decryptor from the cyber criminals behind MedusaLocker. For more information about how to purchase decryption software/tools, victims are instructed to contact criminals via the email address provided. Should the response not arrive within 24 hours, users must send a message to the alternative email address. This must contain a personal ID number, which is listed in the ransom message. To 'prove' their ability to undo the damage, developers of MedusaLocker offer to decrypt one file free of charge so long as the file is no larger than 10 MB. The message further warns that the email address might be blocked soon, and therefore affected users must make contact without delay. The message further states that changing the encrypted data in any way, attempting to decrypt it with third party software, or using private keys from other victims can lead to permanent data loss. Unfortunately, this information is accurate. There are no free decryption tools available that are capable of breaking MedusaLocker decryption. Only the cyber criminals are able to decode data that has been encrypted with their software, however, meeting the ransom demands or communicating with these criminals is not advised. Despite paying, victims of ransomware infections receive no decryption software/tools and/or keys. Therefore, data remains encrypted and useless. The only viable solution is to restore data from a backup, provided one was made prior to the infection and stored separately.

Screenshot of a message encouraging users to pay a ransom to decrypt their compromised data:

MedusaLocker decrypt instructions

Most ransomware programs share similarities. For example, LetoSapphire, and Angus are all similar to MedusaLocker. Malicious software of this type encrypts data and demands ransom payments. Crucial differences are cryptography algorithms (symmetric or asymmetric) used for encryption and ransom size. Digital currencies are preferred by cyber criminals (e.g. cryptocurrencies, pre-paid vouchers, etc.), as these transactions are difficult/impossible to trace. Manual decryption without the involvement of this malicious program's developers is impossible, unless the ransomware is in development or has flaws/bugs. To ensure file safety from data encryption and damaging attacks, store backups on remote servers and/or unplugged storage devices. Ideally, multiple backup copies should be kept in different locations.

How did ransomware infect my computer?

Ransomware and other malware is mainly proliferated through spam campaigns, trojans, software "cracking" (activation) tools, fake updaters and untrustworthy download channels. Massive scale spam campaigns are used to send out deceptive emails containing dangerous attachments (or web-links leading to them). These emails are usually marked as "urgent", "official", "important", and so on. The infectious attachments can be in various file formats (e.g. archive and executable files, Microsoft Office and PDF documents, JavaScript, etc.) and, once opened, download/install malicious software. Trojans are malicious programs designed to cause chain infections. Therefore, they download/install additional malware. "Cracking" tools can download/install malware, rather than activating the licensed products. Fake software updaters infect systems similarly - they abuse weaknesses in outdated programs and/or install malicious content, rather than the promised updates. Peer-to-Peer sharing networks (BitTorrent, Gnutella, eMule, etc.), unofficial and free file-hosting sites, and third party downloaders are classed as untrustworthy and more likely to offer deceptive or bundled software.

Threat Summary:
Name MedusaLocker virus
Threat Type Ransomware, Crypto Virus, Files locker.
Encrypted Files Extension .encrypted
Ransom Demanding Message HOW_TO_RECOVER_DATA.html
Cyber Criminal Contact,
Detection Names AVG (Win32:Malware-gen), BitDefender (Trojan.GenericKD.41882000), ESET-NOD32 (A Variant Of Win32/Filecoder.NYA), Kaspersky (Trojan.Win32.DelShad.ayu), Full List Of Detections (VirusTotal)
Symptoms Cannot open files stored on your computer, previously functional files now have a different extension (for example, my.docx.locked). A ransom demand message is displayed on your desktop. Cyber criminals demand payment of a ransom (usually in bitcoins) to unlock your files.
Distribution methods Infected email attachments (macros), torrent websites, malicious ads.
Damage All files are encrypted and cannot be opened without paying a ransom. Additional password-stealing trojans and malware infections can be installed together with a ransomware infection.
Malware Removal (Windows)

To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Malwarebytes.
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How to protect yourself from ransomware infections

Do not read suspicious or irrelevant emails, especially those received from unknown senders (addresses). Any attachments or web-links found in these messages must never be opened, as this can cause the infection. Only official and trustworthy download sources should be used, as opposed to third party and sharing channels. Installed software should be updated using functions/tools provided by the genuine developers. Programs should be activated using only legal means. Note that "cracking" tools should not be used, as they might download/install malware, rather than activating the licensed products. Have a reputable anti-virus/anti-spyware suite installed. This software should be kept up-to-date, used for regular system scans, and potential threat removals. If your computer is already infected with MedusaLocker, we recommend running a scan with Malwarebytes for Windows to automatically eliminate this ransomware.

Text presented in MedusaLocker ransomware HTML file ("HOW_TO_RECOVER_DATA.html"):

All your data are encrypted!
What happened?
Your files are encrypted, and currently unavailable.
You can check it: all files on you computer has new expansion.
By the way, everything is possible to recover (restore), but you need to buy a unique decryptor.
Otherwise, you never cant return your data.

For purchasing a decryptor contact us by email:
If you will get no answer within 24 hours contact us by our alternate emails:

What guarantees?
Its just a business. If we do not do our work and liabilities - nobody will not cooperate with us.
To verify the possibility of the recovery of your files we can decrypted 1 file for free.
Attach 1 file to the letter (no more than 10Mb). Indicate your personal ID on the letter:
- Attempts of change files by yourself will result in a loose of data.
- Our e-mail can be blocked over time. Write now, loss of contact with us will result in a loose of data.
- Use any third party software for restoring your data or antivirus solutions will result in a loose of data.
- Decryptors of other users are unique and will not fit your files and use of those will result in a loose of data.
- If you will not cooperate with our service - for us, its does not matter. But you will lose your time and data, cause just we have the private key.

The appearance of MedusaLocker ransomware HTML file (GIF):

MedusaLocker HTML file

Screenshot of files encrypted by MedusaLocker (".encrypted" extension):

Files encrypted by MedusaLocker

MedusaLocker ransomware removal:

Instant automatic malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Malwarebytes is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:
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Quick menu:

Step 1

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in "Safe Mode with Networking":

Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in "Safe Mode with Networking":

Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button. In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.

windows 10 safe mode with networking

Video showing how to start Windows 10 in "Safe Mode with Networking":

Step 2

Log in to the account infected with the MedusaLocker virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.

If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.

Video showing how to remove ransomware virus using "Safe Mode with Command Prompt" and "System Restore":

1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.

Boot your computer in Safe Mode with Command Prompt

2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.

system restore using command prompt type cd restore

3. Next, type this line: rstrui.exe and press ENTER.

system restore using command prompt rstrui.exe

4. In the opened window, click "Next".

restore system files and settings

5. Select one of the available Restore Points and click "Next" (this will restore your computer system to an earlier time and date, prior to the MedusaLocker ransomware virus infiltrating your PC).

select a restore point

6. In the opened window, click "Yes".

run system restore

7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining MedusaLocker ransomware files.

To restore individual files encrypted by this ransomware, try using Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of MedusaLocker are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.

To restore a file, right-click over it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the "Restore" button.

Restoring files encrypted by CryptoDefense

If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode making its removal complicated. For this step, you require access to another computer.

To regain control of the files encrypted by MedusaLocker, you can also try using a program called Shadow Explorer. More information on how to use this program is available here.

shadow explorer screenshot

To protect your computer from file encryption ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and EasySync CryptoMonitor, which artificially implant group policy objects into the registry to block rogue programs such as MedusaLocker ransomware.

Note that Windows 10 Fall Creators Update includes a "Controlled Folder Access" feature that blocks ransomware attempts to encrypt your files. By default, this feature automatically protects files stored in the Documents, Pictures, Videos, Music, Favorites as well as Desktop folders.

Controll Folder Access

Windows 10 users should install this update to protect their data from ransomware attacks. Here is more information on how to get this update and add an additional protection layer from ransomware infections.

HitmanPro.Alert CryptoGuard - detects encryption of files and neutralises any attempts without need for user-intervention:

hitmanproalert ransomware prevention application

Malwarebytes Anti-Ransomware Beta uses advanced proactive technology that monitors ransomware activity and terminates it immediately - before reaching users' files:

malwarebytes anti-ransomware

  • The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups. More information on online backup solutions and data recovery software Here.

Other tools known to remove MedusaLocker ransomware:

About the author:

Tomas Meskauskas

Tomas Meskauskas - expert security researcher, professional malware analyst.

I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats. Contact Tomas Meskauskas.

PCrisk security portal is brought by a company RCS LT. Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.

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Removal Instructions in other languages
Malware activity

Global malware activity level today:

Medium threat activity

Increased attack rate of infections detected within the last 24 hours.

QR Code
MedusaLocker virus QR code
A QR code (Quick Response Code) is a machine-readable code which stores URLs and other information. This code can be read using a camera on a smartphone or a tablet. Scan this QR code to have an easy access removal guide of MedusaLocker virus on your mobile device.
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