Remove MZUU Ransomware Virus (+DECRYPT .mzuu Files)

Mzuu malware is a type of computer virus that injects your PC, encrypts your documents, and then asks to pay the money for file decryption. Besides these unpleasant actions, that malware also alters some important settings and can even disable your security tool.

Mzuu Ransomware Summary

NameMzuu virus
TypeSTOP/Djvu Ransomware
DamageAll 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.
Mzuu Removal Tool To use full-featured product, you have to purchase a license. 6 days free trial available.

Mzuu virus – what is it?

Mzuu virus can correctly be described as a STOP/Djvu ransomware family. That sort of computer virus is targeted at single users. This feature supposes that Mzuu does not carry any sort of additional viruses, which usually helps virus of other families to take control of your PC. Since most users do not have anything valuable , there is no reason to download additional viruses that increases the risk of failure of the whole ransomware operation.

The common signs of that ransomware activity is the emersion of .mzuu files in your folders, instead of the document you used to have. The photo.jpg turns into photo.jpg.mzuu, report.xlsx – into report.xlsx.mzuu and so on. You cannot to prevent this process, as well as can’t open these documents – they are encrypted with quite strong algorithm.

Mzuu Virus - encrypted .mzuu files
Mzuu Encrypted Files

You can also see different other signs of malware activity. Abruptly disabled Microsoft Defender and inability to open the popular anti-malware forums or sites, where the removal and decryption guides are posted. You will see how it is conducted in the paragraph below. The malware removal and decryption guide are also available – check below how to delete Mzuu malware and get the .mzuu files back.

How did Mzuu ransomware encrypt my files?

After the malware injection, the Mzuu ransomware establishes a connection with its command and control server. This server is controlled by virus maintainers – people who manage the distribution of this ransomware. Another activity which is conducted by these crooks is answering the emails of victims, who wish to get their files back.

The files are ciphered with one of the strongest encryption algorithm – AES-256. The “256” digit in the name of this algorithms means the power of two – 2^256 for this case. 78-digit number of possible decryption password variations – it is unreal to brute force it. As cipher analysts say, it will need more time than our planet can approximately exist, even when you make use of the most powerful computers. In each folder that contains the encrypted file(s), Mzuu ransomware creates the _readme.txt file with the following contents:


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:

Nonetheless, you can still open some of your files. The Mzuu malware ciphers only the initial 150 KB of each file, but the rest of this document can be accessed. Primarily, it works best with audio/video files, which are likely larger than 150 kilobytes. Not each media player is able to open these files – WinAmp is the best option, since it is free and well-tested. First seconds of each file will be silent – this part is encrypted – but the rest of the file will be accessible like nothing happened.

Is Mzuu ransomware dangerous for my PC?

As it was described several paragraphs before, ransomware is not only about encrypting the files. Mzuu virus makes the changes in your computer in order to prevent searching the malware removal and file decryption guides. Malware does not create the software barrier – it just changes the settings, primarily – networking and security configurations.

Among the networking configurations, the most changed item is the HOSTS configuration file. This text file contains the DNS-address instructions, which are used by the web browsers while requesting to the server. If you add a specific DNS-address for the certain website, your web browser will connect that page through that DNS next time. Ransomware alters that file, adding the non-existent DNS, so any of the web browsers will show you the “Unable to resolve the DNS-address” error.

Error 404

Other changes done by the ransomware are aimed at prevention of fast detection of itself, and also disabling the installation of the majority of anti-malware programs. Mzuu ransomware implements several modifications in Group Policies – the system setting interface which allows to change the rights of each app. In such a way, the virus disables the Microsoft Defender and various other antivirus programs, and also disables the launch of antivirus installation files.

How did I get infected?

Throughout the whole term while STOP/Djvu family is active, it was using questionable programs as a primary method of ransomware injection. Under the term of questionable programs I mean programs that are already not supported by the maintainer and spread through the third-party websites. These programs may be cracked, to make them usable without purchasing any license. Another example of such a program type is different hacking tools – cheat engines, keygens, Windows activation tools and so on.

This sort of applications may be distributed in many ways – through the website that offers a downloading link, or through the p2p networks – ThePirateBay, eMule and so on. All these sources are well-known as the biggest computer piracy websites. Folks use these pages to get various programs or games for free, even if these programs must be purchased. No one can prevent the users who crack these programs from adding viruses of some sort to the files of the hacked app. Hacktools, meanwhile, are created for outlaw purposes, so their creators may easily add the virus under the guise of some program element.

injecting viruses into program
While adding the jumps on license checking, hackers can easily inject malicious code into the program

These hacked programs, regardless of their source, are one of the most often carriers for various viruses, and 100% the most popular one for Mzuu virus. The best solution is to avoid making use of it, and not only because of malware injection risks. Avoiding the license buying is an illegal action, and both hackers and users who make use of cracked apps fall under the charge of piracy.

How do I remove Mzuu ransomware?

The Mzuu ransomware is extremely hard to remove manually. In fact, because of the amount of alterations it makes into your PC, it is almost impossible to spot them all and fix. The best decision is to use antivirus programs. But which one to choose?

You can read the advices to use Microsoft Defender, which is already inside of your Windows. But as it was mentioned earlier, the majority of STOP/Djvu ransomware examples disable it even before the encryption process. Making use of the third-party program is the only possible option – and I can offer you the GridinSoft Anti-Malware as an option for this case. It has perfect detection abilities, so the ransomware will not be missed. It is also capable of system repairing, which is heavily demanded after the Mzuu virus attack.

To remove Mzuu malware infections, scan your computer with legitimate antivirus software.

  • Download and install GridinSoft Anti-Malware by the button above. After the installation process, you will see an offer to start a 6-day free trial. In this term, the security tool has its full functionality, so you will surely be able to both remove the virus and fix your computer. To activate a free trial, you just need to type your email address.
  • Free trial activation GridinSoft Anti-Malware

  • After activating the trial, launch the full scan of your PC. It will last for about 15-20 minutes, and check each folder you have in your system. Ransomware will not hide!
  • Full scan in GridinSoft Anti-Malware

  • When the scan is over, press the Clean Now button to wipe out the Mzuu ransomware and all other malware detected by a program.
  • Clean the viruses

    After the ransomware removal, you can go to file decryption. Ransomware removal is required to prevent the repeating ciphering of your files: while Mzuu ransomware is active, it will not pass any unencrypted file.

    How to decrypt the .mzuu files?

    There are two ways to recover your files after a Mzuu ransomware attack. First one and the most popular is file decryption. It is performed with a special program, designed by Emsisoft, and named Emsisoft Decryptor for STOP/Djvu. This program is absolutely free. Analysts update its decryption keys databases as often as possible, so you will definitely get your files back, sooner or later.

    Another way to get your files back is to try to recover them from your disk drives. Since Mzuu virus deletes them and substitutes with an encrypted copy, the residue of the files are still kept on the disk. After the deletion, the information about them is removed from the file system, but not from a disk. Special apps, like PhotoRec, are able to recover these files. It is free, too, and may also be used for file recovery in case when you have deleted something unintentionally.

    Decrypting the .mzuu files with Emsisoft Decrypter for STOP/Djvu

    Download and install Emsisoft Decrypter tool. Agree with its EULA and continue to the interface.

    Emsisoft Decrypter EULA

    The interface of this program is extremely easy. All you have to do is to select the folder where the encrypted files are stored, and wait. If the program has the decryption key which corresponds to your ransomware case – it will decrypt it.

    Emsisoft Decrypter decryption process

    During the use of Emsisoft Decrypter for STOP/Djvu, you may observe various error messages. Don’t worry, that does not mean that you did something wrong or a program does not work properly. Each of these errors refer to a specific case. Here is the explanation:

    Error: Unable to decrypt file with ID: [your ID]

    The program does not have a corresponding key for your case. You need to wait for some time until the key database will be updated.

    No key for new variant online ID: [your ID]

    Notice: this ID appears to be an online ID, decryption is impossible.

    This error means that your files are encrypted with an online key. In such a case, the decryption key is unique and stored on the remote server, controlled by crooks. Unfortunately, the decryption is impossible.

    Result: No key for new variant offline ID: [example ID]

    This ID appears to be an offline ID. Decryption may be possible in the future.

    Ransomware uses the offline key to encrypt your files. This key is not unique, so you likely have it in common with another victim. Since offline keys must be collected, too, it is important to keep calm and wait until the analysts team finds one which will fit your case.

    Remote name could not be resolved

    This error indicates that the program has problems with DNS on your computer. That’s a clear sign of malicious alterations in your HOSTS file. Reset it using the official Microsoft guide.

    Recovering the .mzuu files with PhotoRec tool

    PhotoRec is an open-source tool, which is created to recover the deleted or lost files from the disk drive. It checks each disk sector for the remains of deleted files, and then attempts to recover them. That app is able to recover the files of more than 400 different extensions. Because of the described feature of ransomware encryption mechanism, it is possible to use this tool to get the original, unencrypted files back.

    Download PhotoRec from the official website. It is absolutely free, however, its developer warns that he does not guarantee that this program will be 100% effective for file recovery purposes. Moreover, even paid apps can barely give you such a guarantee, because of the chain of random factors that can make the file recovery harder.

    Unzip the downloaded archive to the folder you like. Don’t worry because of its name – TestDisk – this is the name of the utility developed by the same company. They decided to spread it together since PhotoRec and TestDisk are often used together. Among the unzipped files, search for qphotorec_win.exe file. Run this executable file.

    PhotoRec and TestDisk

    Before you can start the recovery process, you need to specify several settings. In the drop-down list, choose the logic disk where the files were stored before the encryption.

    PhotoRec recovering choose disk drive

    Then, you need to specify the file formats you need to recover. It may be difficult to scroll all 400+ formats, luckily, they are sorted by alphabetical order.

    PhotoRec file formats

    Finally, name the folder you want to use as a container for recovered files. The program will likely dig out a lot of useless files, which were deleted intentionally, so desktop is a bad solution. The best option is to use the USB-drive.

    PhotoRec recovery drive

    After these easy manipulations, you may just press the “Search” button (it turns active if you specified all required parameters). The recovery process may take several hours, so keep patient. It is recommended not to use the computer during this term, since you may overwrite some files you are intending to recover.

    Frequently Asked Questions

    ✔️Are the files encrypted by Mzuu virus dangerous?

    No. Mzuu files is not a virus, it is not able to inject its code into the files and force them to execute it. The .EXT files are just the same as regular ones, but encrypted and cannot be opened in the usual way. You may store it together with normal files without any fears.

    ✔️Is it possible that antivirus software will delete the encrypted files?

    As I have mentioned in a previous paragraph, encrypted files are not dangerous. Hence, good anti-malware programs like GridinSoft Anti-Malware will not trigger on them. Meanwhile, some of the “disk cleaning tools” may remove them, stating that they belong to the unknown format and are likely broken.

    ✔️The Emsisoft tool says my files are encrypted with the online key and cannot be decrypted. What do I need to do?

    It is very unpleasant to hear that the files you have are likely lost. Ransomware creators lie a lot in order to scare their victims, but they tell the truth in claims about the strength of the encryption. Your decryption key is stored on their servers, and it is impossible to select it because of the strength of the encryption mechanism.

    Try other recovery methods – through the PhotoRec, or using the previously created backups. Search for the previous versions of these files – getting back a part of your dissertation, for example, is better than missing it all.

    Last option is just waiting. When the cyber police caughts the crooks who create and distribute ransomware, first get the decryption keys and publish it. Emsisoft analysts will surely take these keys and add them to the Decryptor databases. In some cases, malware creators may publish the rest of the keys when they stop their activity.

    ✔️Not all of my .mzuu files are decrypted. What do I need to do?

    The situation when the Emsisoft Decryptor failed to decrypt several files usually happens when you have not added the correct file pair for the certain file format. Another case when this problem may appear is when some problem occurred during the decryption process – for example, RAM limit reached. Try to perform the decryption process once again.

    Another situation when the Decryptor app may leave your files unencrypted is when ransomware uses different keys for certain files. For example, it may use offline keys for a short period of time when it has connection issues. The Emsisoft tool is not able to check both key types simultaneously, so you need to launch the decryption again, in order to repeat the process.

    Helga Smith

    I was always interested in computer sciences, especially data security and the theme, which is called nowadays "data science", since my early teens. Before coming into the Virus Removal team as Editor-in-chief, I worked as a cybersecurity expert in several companies, including one of Amazon's contractors. Another experience: I have got is teaching in Arden and Reading universities.

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