Mmnn ransomware (Virus Removal Guide) - Recovery Instructions Included

Mmnn virus Removal Guide

What is Mmnn ransomware?

Mmnn ransomware – file locking malware that encrypts documents and other files on the system with RSA cipher

Mmnn ransomwareMmnn ransomware is a file locking virus that might result in permanent data loss

Mmnn ransomware is a type of malware that locks pictures, documents, databases, PDF, and other files on the host system. Being a variant of the prolific family Djvu, this virus follows similar behavioral pattern as its predecessors – it locks data with the help of a strong encryption algorithm RSA,[1] appends an extension to each of the files (in this case, .mmnn is added), and then drops a ransom note _readme.txt.

Inside the ransom note, users can find a message from Mmnn virus authors. It claims that, in order to regain access to data, they need to send an email via or, and then pay the ransom – $490 in Bitcoins. If the requirement is not fulfilled within 72 hours, the Mmnn ransomware decryptor price increases to $980. However, paying criminals is risky, as they might never send the required tool after the money transfer. Instead, there are other recovery methods that might work, such as Emsisoft's decryption tool that is continuously being updated, or third-party recovery software might also be useful in some cases.

Name Mmnn ransomware
Type File locking virus, cryptomalware
Family Djvu ransomware family
File extension The virus locks all user files and appends .mmnn extension; example of encrypted file picture.jpg -> picture.jpg.mmnn
Cipher A sophisticated asymmetric RSA encryption algorithm is used for file locking process
Ransom note _readme.txt is dropped on the desktop, as well as all the folders where locked data is located
Contact details Contact emails vary from version to version; this time, crooks ask to contact them via or for the negotiation purposes
Ransom size The attackers ask to pay $490 in Bitcoin for the decryption software; this sum doubles if the demands are not fulfilled within 72 hours post-infection
  • Deletes Shadow Volume Copies
  • Modifies Windows registry
  • Prevents users from visiting security-related sites by altering Windows “hosts” file
  • Inserts data-stealing module into web browsers
  • May be installed along with a Trojan, such as AZORult
File recovery Without backups, file recovery might be difficult. Emsisoft's decryptor might be helpful if the malware has used an offline ID to lock files. Additionally, third-party recovery tools may sometimes be successful when trying to regain access to .mmnn locked files – you can find download links and usage instructions below
Malware removal It is vital to get rid of ransomware before proceeding with file recovery, but only after making copies of locked files. Termination can only be achieved with reputable anti-malware tools, such as SpyHunter 5Combo Cleaner or Malwarebytes
System fix In case your computer is crashing or is not working as prior to ransomware infection, you can fix virus damage with repair software FortectIntego – it could help you avoid the lengthy process of the OS reinstallation

It is important to remove Mmnn ransomware from the system as soon as possible because variants of this malware family were previously spotted inserting a data-stealing module into Google Chrome, Mozilla Firefox, and other popular browsers. As a result, users who enter their sensitive data, such as banking details, may deliver this information to malicious actors without realizing it.

Besides, the Mmnn file virus modifies Windows “hosts” file – it appends the IP address of websites that focus on Mmnn ransomware removal instructions. As a result, users will be unable to contact them. To stop this from happening, users should go to the following location on their Windows machines and delete the “hosts” file:


It is important to note that Mmnn ransomware can employ various tactics and methods in order to operate on the system without interruptions. For example, before proceeding with data encryption, the malware modifies the Windows registry to establish persistence, deletes Shadow Volume Copies to prevent data recovery, disables Windows Repair, and performs many more system modifications. As a result, Windows may get corrupted, and victims will be forced to reinstall it after malware termination. If that is the case, we recommend using FortectIntego repair tool, as it can fix Mmnn virus damage.

After the preparations are complete, Mmnn ransomware will begin the encryption process. It targets most common used file types, such as .pdf, .doc, .zip, .txt, .mp4, .jpg, .dat, .xml, etc., although it skips system files, as well as most executables. During this time, the malware will show a fake Windows update Window that is designed to mask the original purpose of the data encryption task. After that, users will quickly notice that all their personal files are marked with .mmnn extension, their icons are blank, and that they can no longer access them.

Note: malware infection and data encryption are two separate processes – many users confuse these two. What it means is that even if you get rid of Mmnn ransomware infection (termination of malicious settings and files imported by malware), it will not transform your data back to the original state.

Mmnn ransomware locked filesOnce Mmnn ransomware encrypts files, users will no longer be able to access them

Mmnn ransomware decryption options

Djvu ransomware, otherwise known as STOP ransomware, was first spotted in the wild back in December 2017, and since then, more than 200 variants were released. Currently, malicious actors deliver new versions regularly – most recent ones append .rooe, .bboo, .alka, .repp, and .btos file extensions. Since then, security researchers tried to battle this prolific family and were sometimes successful with tools like STOPDecrypter, which worked in particular situations.

In October 2019, security researchers from Emsisoft managed to create a decryption tool that could help victims to recover files for free, although it only worked for versions released before August that year. Unfortunately, Mmnn ransomware belongs to the new surge of variants that apply an improved encryption algorithm RSA, so data can no longer be decrypted.

Nevertheless, at that time, researchers also delivered a decryption tool that could also sometimes help victims even with the newest variants – and it is used to this day. Unfortunately, the decryptor is only viable when the encryption process of Mmnn ransomware (or another new version) was performed when the malware could not contact its Command & Control servers, i.e., it used an offline ID to lock data.

Hackers behind Mmnn ransomware virus deliver the following message to victims:


Don't worry, you can return all your files!
All your files like photos, databases, documents and other important are encrypted with strongest encryption and unique key.
The only method of recovering files is to purchase decrypt tool and unique key for you.
This software will decrypt all your encrypted files.
What guarantees you have?
You can send one of your encrypted file from your PC and we decrypt it for free.
But we can decrypt only 1 file for free. File must not contain valuable information.
You can get and look video overview decrypt tool:
Price of private key and decrypt software is $980.
Discount 50% available if you contact us first 72 hours, that's price for you is $490.
Please note that you'll never restore your data without payment.
Check your e-mail “Spam” or “Junk” folder if you don't get answer more than 6 hours.

To get this software you need write on our e-mail:

Reserve e-mail address to contact us:

Your personal ID:

Providing a test decryption option now became a common practice among cybercriminals, as they try to establish a false sense of security. In other words, they are trying to convince victims that decryption software for Mmnn ransomware will follow as soon as they pay the ransom in Bitcoin.

Unfortunately, that is not entirely true – at least not always. There have been plenty of documented cases where ransomware developers did not respond and did not provide the tool after the payment. Therefore, if you decide to pay for Mmnn ransomware decryptor, keep in mind that you might lose not only your files but also the money.

Therefore, rather refer to the data recovery section below – we provide download links and usage instructions of some third-party tools that may help you recover at least some of Mmnn ransomware-encrypted files.

Mmnn ransomware virusMmnn is a ransomware-type virus that comes from a prolific malware family - Djvu

Protect your computer from ransomware infections

Most users who get infected with ransomware never had to deal with it before. Therefore, they do not immediately understand the implications of the infection; i.e., it usually results in permanent data loss. Luckily, there are some options that might help for some users, although it is not a rule.

According to security researchers, about 99% of infections of Djvu occur when users download pirated application installers or software cracks/loaders/keygens from various insecure websites. Additionally, ransomware may also be delivered directly via adware bundles (as it happened with .rumba variant).[2] Therefore, it is vital staying away from such dangerous sites and either opt for free alternatives of the program or buying or buying it from the official sources.

Nevertheless, many users are still willing to risk it – those who visit pirated software sites are usually aware that they are filled with malware. Remember that ransom demands reach as high as $980 – a far larger sum than a paid version of most applications.

Additionally, security experts[3] also advise practice the following safety measures:

  • Backup your personal files regularly;
  • Employ reputable anti-malware software and keep it updated;
  • Apple security updates as soon as they are released;
  • Use strong passwords for all your accounts;
  • Do not use a default port (3389) for your Remote Desktop connections;
  • Do not open spam email attachments or click on links inside;
  • Employ additional tools for security, such as ad-block, Firewall, VPN, etc.

Terminate Mmnn ransomware the correct way

Those who never had to deal with a ransomware infection may be baffled of what to do next. It is important not to start from the wrong action, such as immediately using anti-malware to remove Mmnn ransomware or attempt to use backups for file recovery.

Recovery tools or Mmnn ransomware removal may corrupt encrypted data, and even a working decryptor would not be able to save it anymore. Therefore, the first step should be backup of already encrypted files – you can either copy them to an external drive or place them on a remote server, like Google Drive. Once you complete this, you can then proceed with the Mmnn virus termination process.

The only way to get rid of malware is to employ a powerful anti-malware tool that can recognize the threat.[4] perform a full system scan – this will guarantee that all the malicious files are deleted. Only then you may attempt the file recovery process, which also depends on your particular case.

do it now!
Fortect Happiness
Intego Happiness
Compatible with Microsoft Windows Compatible with macOS
What to do if failed?
If you failed to fix virus damage using Fortect Intego, submit a question to our support team and provide as much details as possible.
Fortect Intego has a free limited scanner. Fortect Intego offers more through scan when you purchase its full version. When free scanner detects issues, you can fix them using free manual repairs or you can decide to purchase the full version in order to fix them automatically.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Fortect, try running SpyHunter 5.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Intego, try running Combo Cleaner.

Getting rid of Mmnn virus. Follow these steps

Manual removal using Safe Mode

In case Mmnn ransomware is tampering with your security application, access Safe Mode with Networking:

Important! →
Manual removal guide might be too complicated for regular computer users. It requires advanced IT knowledge to be performed correctly (if vital system files are removed or damaged, it might result in full Windows compromise), and it also might take hours to complete. Therefore, we highly advise using the automatic method provided above instead.

Step 1. Access Safe Mode with Networking

Manual malware removal should be best performed in the Safe Mode environment. 

Windows 7 / Vista / XP
  1. Click Start > Shutdown > Restart > OK.
  2. When your computer becomes active, start pressing F8 button (if that does not work, try F2, F12, Del, etc. – it all depends on your motherboard model) multiple times until you see the Advanced Boot Options window.
  3. Select Safe Mode with Networking from the list. Windows 7/XP
Windows 10 / Windows 8
  1. Right-click on Start button and select Settings.
  2. Scroll down to pick Update & Security.
    Update and security
  3. On the left side of the window, pick Recovery.
  4. Now scroll down to find Advanced Startup section.
  5. Click Restart now.
  6. Select Troubleshoot. Choose an option
  7. Go to Advanced options. Advanced options
  8. Select Startup Settings. Startup settings
  9. Press Restart.
  10. Now press 5 or click 5) Enable Safe Mode with Networking. Enable safe mode

Step 2. Shut down suspicious processes

Windows Task Manager is a useful tool that shows all the processes running in the background. If malware is running a process, you need to shut it down:

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Click on More details.
    Open task manager
  3. Scroll down to Background processes section, and look for anything suspicious.
  4. Right-click and select Open file location.
    Open file location
  5. Go back to the process, right-click and pick End Task.
    End task
  6. Delete the contents of the malicious folder.

Step 3. Check program Startup

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Go to Startup tab.
  3. Right-click on the suspicious program and pick Disable.

Step 4. Delete virus files

Malware-related files can be found in various places within your computer. Here are instructions that could help you find them:

  1. Type in Disk Cleanup in Windows search and press Enter.
    Disk cleanup
  2. Select the drive you want to clean (C: is your main drive by default and is likely to be the one that has malicious files in).
  3. Scroll through the Files to delete list and select the following:

    Temporary Internet Files
    Recycle Bin
    Temporary files

  4. Pick Clean up system files.
    Delete temp files
  5. You can also look for other malicious files hidden in the following folders (type these entries in Windows Search and press Enter):


After you are finished, reboot the PC in normal mode.

Remove Mmnn using System Restore

You may be able to delete the virus with System Restore:

  • Step 1: Reboot your computer to Safe Mode with Command Prompt
    Windows 7 / Vista / XP
    1. Click Start Shutdown Restart OK.
    2. When your computer becomes active, start pressing F8 multiple times until you see the Advanced Boot Options window.
    3. Select Command Prompt from the list Select 'Safe Mode with Command Prompt'

    Windows 10 / Windows 8
    1. Press the Power button at the Windows login screen. Now press and hold Shift, which is on your keyboard, and click Restart..
    2. Now select Troubleshoot Advanced options Startup Settings and finally press Restart.
    3. Once your computer becomes active, select Enable Safe Mode with Command Prompt in Startup Settings window. Select 'Enable Safe Mode with Command Prompt'
  • Step 2: Restore your system files and settings
    1. Once the Command Prompt window shows up, enter cd restore and click Enter. Enter 'cd restore' without quotes and press 'Enter'
    2. Now type rstrui.exe and press Enter again.. Enter 'rstrui.exe' without quotes and press 'Enter'
    3. When a new window shows up, click Next and select your restore point that is prior the infiltration of Mmnn. After doing that, click Next. When 'System Restore' window shows up, select 'Next' Select your restore point and click 'Next'
    4. Now click Yes to start system restore. Click 'Yes' and start system restore
    Once you restore your system to a previous date, download and scan your computer with FortectIntego and make sure that Mmnn removal is performed successfully.

Bonus: Recover your data

Guide which is presented above is supposed to help you remove Mmnn from your computer. To recover your encrypted files, we recommend using a detailed guide prepared by security experts.

If your files are encrypted by Mmnn, you can use several methods to restore them:

Data Recovery Pro method

Data recovery software may be able to retrieve at least some files from your hard drive (the less you use your PC after the infection, the bigger chances of success).

  • Download Data Recovery Pro;
  • Follow the steps of Data Recovery Setup and install the program on your computer;
  • Launch it and scan your computer for files encrypted by Mmnn ransomware;
  • Restore them.

Make use of Windows Previous Versions feature

The method can only be applied if you had System Restore enabled prior to malware attack.

  • Find an encrypted file you need to restore and right-click on it;
  • Select “Properties” and go to “Previous versions” tab;
  • Here, check each of available copies of the file in “Folder versions”. You should select the version you want to recover and click “Restore”.

ShadowExplorer may be the only solution

Mmnn file virus may have failed to delete Shadow Volume Copies. In this case, you should be able to recover all the locked files with ShadowExplorer.

  • Download Shadow Explorer (;
  • Follow a Shadow Explorer Setup Wizard and install this application on your computer;
  • Launch the program and go through the drop down menu on the top left corner to select the disk of your encrypted data. Check what folders are there;
  • Right-click on the folder you want to restore and select “Export”. You can also select where you want it to be stored.

Try Emsisoft's decryption tool

In case of malware used an offline ID to encrypt your files, there is a chance Emsisoft's decryptor will help you to recover your data. In another case, you may also be able to restore some file types with the help of security vendor Dr. Web, although the service is not free.

Finally, you should always think about the protection of crypto-ransomwares. In order to protect your computer from Mmnn and other ransomwares, use a reputable anti-spyware, such as FortectIntego, SpyHunter 5Combo Cleaner or Malwarebytes

How to prevent from getting ransomware

Stream videos without limitations, no matter where you are

There are multiple parties that could find out almost anything about you by checking your online activity. While this is highly unlikely, advertisers and tech companies are constantly tracking you online. The first step to privacy should be a secure browser that focuses on tracker reduction to a minimum.

Even if you employ a secure browser, you will not be able to access websites that are restricted due to local government laws or other reasons. In other words, you may not be able to stream Disney+ or US-based Netflix in some countries. To bypass these restrictions, you can employ a powerful Private Internet Access VPN, which provides dedicated servers for torrenting and streaming, not slowing you down in the process.

Data backups are important – recover your lost files

Ransomware is one of the biggest threats to personal data. Once it is executed on a machine, it launches a sophisticated encryption algorithm that locks all your files, although it does not destroy them. The most common misconception is that anti-malware software can return files to their previous states. This is not true, however, and data remains locked after the malicious payload is deleted.

While regular data backups are the only secure method to recover your files after a ransomware attack, tools such as Data Recovery Pro can also be effective and restore at least some of your lost data.

About the author
Julie Splinters
Julie Splinters - Anti-malware specialist

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