MoonCrypter Ransomware

Also Known As: MoonCrypter virus
Distribution: Low
Damage level: Severe

MoonCrypter ransomware removal instructions

What is MoonCrypter?

First discovered by malware security researcher, Karsten Hahn, MoonCrypter is a virus based on an open-source ransomware project called Hidden Tear. Once infiltrated, MoonCrypter encrypts stored data using RSA-1024 and AES-256 encryption algorithms. During encryption, the virus appends filenames with the ".cmoon" extension (for example, "sample.jpg" is renamed to "sample.jpg.cmoon"). Following successful encryption, MoonCrypter opens a pop-up window and creates two text files: "_readmyransom.txt" (placed in each existing folder) and "ReadIt.txt" (placed on the desktop).

The text files contain a ransom-demand message stating that files are encrypted and that the victim must pay a ransom to restore them. As mentioned above, MoonCrypter encrypts data using RSA and AES cryptographies. Thus, two decryption keys are generated - restoring files without them is impossible. Cyber criminals store these keys on a remote server and victims are encouraged to pay a ransom to receive them. The cost is currently unconfirmed, however, this usually fluctuates between the equivalent of $500 and $1500 in Bitcoins. In any case, never pay any ransom or attempt to contact cyber criminals. Research shows that these people often ignore victims once payments are submitted. There is a high probability that paying will not deliver any positive result - you will probably be scammed, lose your money, and support cyber criminals' malicious businesses. Unfortunately, there are no tools capable of restoring files encrypted by MoonCrypter ransomware. Therefore, you can only restore your files/system from a backup.

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

MoonCrypter decrypt instructions

MoonCrypter has very similar characteristics to SyncCrypt, Dharma, GlobeImposter, Nemesis, and dozens of other ransomware-type viruses. As with MoonCrypter, these malware infections also encrypt files and make ransom demands. The only major differences between these viruses are size of ransom and type of encryption algorithm used. Research shows that most ransomware employs algorithms that generate unique decryption keys. Therefore, restoring files manually without developers' help (you are not advised to contact them) is mostly impossible.

How did ransomware infect my computer?

Ransomware-type viruses are often distributed using fake software updaters, trojans, unofficial software distribution sources (freeware download websites, free file hosting websites, peer-to-peer networks, etc.), and spam emails (malicious attachments). Fake update tools exploit old software bugs/flaws to infect systems. Third party software distribution sources often present malicious files as legitimate software. Spam emails might contain attachments (for example, JavaScript files, MS Office documents with macros, etc.) designed to download/install malware.

How to protect yourself from ransomware infections?

To prevent ransomware infections, be very cautious when browsing the Internet. Never open files received from suspicious emails or download software from unofficial sources. Furthermore, use a legitimate anti-virus/anti-spyware suite and keep installed applications up-to-date. Bear in mind, however, that criminals proliferate malware via fake updaters. Therefore, using third party tools to update installed apps is very risky. The key to computer safety is caution.

Message presented in MoonCrypter ransomware text files ("_readmyransom.txt" and "ReadIt.txt"):

All your files are LOST FOREVER IN THIS DIRECTORY!!!!!
Excepted if you want to pay : follow this link :
hxxp://10.10.3.1/panel/decipher.php
L'UUID est : FE69CC44
Le mot de passe encrypté RSA est : -

The appearance of MoonCrypter pop-up (GIF):

MoonCrypter pop-up

Screenshot of files encrypted by MoonCrypter (".cmoon" extension):

Files encrypted by MoonCrypter

MoonCrypter ransomware removal:

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 MoonCrypter 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.


Download remover for MoonCrypter virus
1) Download and install   2) Run system scan   3) Enjoy your clean computer!

By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Reimage.

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 MoonCrypter 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 MoonCrypter 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 MoonCrypter 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 MoonCrypter, 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 MoonCrypter ransomware.

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 MoonCrypter ransomware: