Mr-X666 Ransomware

Also Known As: Mr-X666 virus
Distribution: Low
Damage level: Severe

Mr-X666 ransomware removal instructions

What is Mr-X666?

Discovered by Michael Gillespie and belonging to the GlobeImposter ransomware family, Mr-X666 is a malicious ransomware-type program that cyber criminals distribute to extort money (cryptocurrency) from innocent people. This is achieved by encrypting files stored on computers and making ransom demands to restore them. This ransomware renames encrypted files by adding the ".Mr-X666" extension. For example, "1.jpg" is renamed by Mr-X666 to "1.jpg.Mr-X666". In addition, Mr-X666 creates a ransom message within a file called "HOW TO BACK YOUR FILES.txt" and places the file in all folders that contain encrypted files.

Within the "HOW TO BACK YOUR FILES.txt" ransom message, cyber criminals inform victims that all files were encrypted, and to decrypt them, they must use a decryption tool. To acquire this tool, they are encouraged to contact the developers of Mr-X666 by sending an email to or (the email message must include a personal ID). Victims should then receive instructions on how to pay for a decryption tool. They promise to send this as soon as they receive the money. As 'proof' that they have this tool, they offer free decryption of some files, which must also be sent to one of the aforementioned email addresses with the assigned unique ID. Mr-X666's developers assure victims that only they can provide a decryption tool. They urge victims not to attempt to decrypt data using any other tools, since this can supposedly lead to permanent data loss. Unfortunately, that is accurate: only the cyber criminals who developed Mr-X666 can decrypt data encrypted. Most cyber criminals use cryptography algorithms (symmetric or asymmetric) that make encryption 'uncrackable'. In summary, encrypted files cannot be decrypted without using specific tools. Unfortunately, in most cases, only the ransomware developers have the tools capable of file decryption. There is no software available that can decrypt data encrypted by Mr-X666 free of charge (at least not at the moment). Furthermore, people who develop programs such as Mr-X666 cannot be trusted, even if their ransom demands are met. They send no decryption tools and simply ignore victims. Therefore, we recommend that you maintain regular backups and restore all files from there.

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

Mr-X666 decrypt instructions

Mr-X666 is one of many other programs of this type. Some examples of other ransomware-type programs are CMG, L1LL, and Prus. Most encrypt data and display ransom messages. The main differences between these programs are cryptography used to encrypt files and cost of decryption tool (ransom amount). Typically, decryption without the involvement of cyber criminals is possible only if ransomware is still in development, has unfixed bugs/flaws, and so on. To avoid data loss, maintain regular backups and keep them stored on remote servers (such as Cloud) or unplugged/disconnected storage devices.

Mr-X666 ransomware technical analysis:

  • Detection names: Avast (Win32:Malware-gen), BitDefender (Generic.Ransom.GlobeImposter.B328...), Kaspersky (, ESET-NOD32 (a variant of Win32/Filecoder.NUW)
  • Full list of antivirus detections: VirusTotal
  • Sample first submitted: 2019-03-21 (created 2019-03-18)

How did ransomware infect my computer?

Ransomware developers use various ways to proliferate these computer infections including spam campaigns (emails). They send emails with attached malicious files that, once opened, download and install ransomware or other high-risk computer infections. Attached files are usually Microsoft Office or PDF documents, archive files such as RAR, ZIP, executables (.exe files), JavaScript files, and so on, however, these files can cause computer infections only if they are opened. 'Trojans' also infect computers with ransomware - these are malicious programs that cause chain infections. When installed, they download and install other malicious programs. Dubious software download sources such as untrustworthy, unofficial websites (freeware download websites, free file hosting websites), Peer-to-Peer networks (torrent clients, eMule, and so on), third party downloaders, and other similar channels are used by cyber criminals who attempt to infect computers. They present viruses as legitimate files. When people download and open them, however, they cause computer infections. Another way to proliferate ransomware and other malicious programs is through fake software updaters. These tools often download and install infections rather than installing updates, or they exploit bugs/flaws of installed and outdated software. Use of software 'cracking' tools can also lead to computer infection. These supposedly allow people to bypass paid activation of software or operating systems, however, they often install malicious programs.

Threat Summary:
Name Mr-X666 virus
Threat Type Ransomware, Crypto Virus, Files locker.
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 request a ransom payment (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.

To eliminate malware infections our security researchers recommend scanning your computer with Spyhunter.
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How to protect yourself from ransomware infections?

To keep computers safe from various infections, do not open attachments or links that are presented in emails received from unknown, suspicious addresses. Generally, they are included in irrelevant emails that are presented as legitimate and official. Additionally, download software from official, trustworthy websites and using direct links. Avoid dubious channels such as torrents, eMule, dubious websites, third party downloaders and other such tools. Installed software and operating systems should be updated using tools or implemented functions that are provided by official developers only. Software activation should not be done using third party ('cracking') tools. They are illegal and can be used to cause computer infections. Keep your computer protected by having reputable anti-spyware or anti-virus software installed and keep it enabled at all times. These programs detect and eliminate various threats before they can do any damage. If your computer is already infected with Mr-X666, we recommend running a scan with Spyhunter for Windows to automatically eliminate this ransomware.

Text presented in Mr-X666 ransomware text file :



To recover data you need decrypt tool.

To get the decrypt tool you should:

1.In the letter include your personal ID! Send me this ID in your first email to me!
2.We can give you free test for decrypt few files (NOT VALUE) and assign the price for decryption all files!
3.After we send you instruction how to pay for decrypt tool and after payment you will receive a decryption tool!
4.We can decrypt few files in quality the evidence that we have the decoder.




Screenshot of files encrypted by Mr-X666 (".Mr-X666" extension):

Files encrypted by Mr-X666

Mr-X666 ransomware removal:

Instant automatic malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Spyhunter 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 Mr-X666 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 Mr-X666 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 Mr-X666 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 Mr-X666 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 Mr-X666, 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 Mr-X666 ransomware.

Note that Windows 10 Fall Creators Update includes "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 Mr-X666 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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Malware activity

Global malware activity level today:

Medium threat activity

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

QR Code
Mr-X666 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 Mr-X666 virus on your mobile device.
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