What is Mmuz virus?
Mmuz virus is a new ransomware that attacks the victim’s computer by encrypting files and demanding a ransom for decrypting them. The ransomware attack can lead to data loss and financial losses. Mmuz encrypts files, renames them by appending the .mmuz extension, and creates files named “_readme.txt” containing the ransom demand message. For example, a file named “document.docx” will be renamed to “document.docx.mmuz”, a “image.jpg” file to “image.jpg.mmuz”, “invoice.pdf” to “invoice.pdf.mmuz”, and so on.
- What is Mmuz virus?
- Remove Mmuz virus (ransomware)
- Decrypt .mmuz files
- Restore .mmuz files
- Video Guide
Mmuz ransomware is really a nasty malware that is the 428th version of the STOP (DJVU) ransomware. It infects the system when the user downloads or runs malware infected files. Criminals lure unwary users into downloading ransomware by hiding malicious code within cracked versions of paid software, free software, key generators, and so on. Upon execution, an instance of Mmuz virus is installed on victim’s computer.
Once installed on a computer, Mmuz encrypts files located on the drives connected to the computer. It uses a strong algorithm and a long key to encrypt files. If, before encrypting the files, the Mmuz ransomware was able to establish a connection with its command-and-control (C&C) server, then it uses so called ‘online key’ that is unique to each infected computer. In case when the Mmuz virus cannot connect to its command server, it uses the so-called offline key. This key, unlike the online key, is the same for all infected computers and can be determined by security researchers.
In the process of encrypting files, Mmuz tries to encrypt all files on the computer, therefore, to speed up the encryption process, it does not encrypt all the contents of the files, but only the first 154kb. At the same time, there are files that the virus does not encrypt: files located in the Windows system directories, files with the extension .bat, ini, .sys, .dll, .lnk and files with the name ‘_readme.txt’. All other files can be encrypted, regardless of where they are located: on the internal disk, external device or cloud storage. Thus, the following common file types can be encrypted:
.wbmp, .srf, .xdl, .rw2, .mddata, .odt, .dcr, .mpqge, .bkp, .ztmp, .cr2, .sid, .big, .arw, .rofl, .orf, .sidd, .kdc, .1, .wdb, .tax, .wps, .wgz, .forge, .hkx, .dazip, .m2, .xyp, .wma, .xml, .rgss3a, .desc, .mef, .litemod, .zabw, .z, .wmv, .rar, .mdbackup, .xlgc, .sie, .pptx, .rtf, .zdc, .ff, .bsa, .odb, .map, .bc6, .psd, .wp6, .jpg, .gdb, .xls, .z3d, .wpl, .flv, .dwg, .syncdb, .m3u, .y, .wmv, .xbdoc, .xyw, .pak, .qic, .2bp, .sb, .x3d, .icxs, .rim, .xlsb, .indd, .7z, wallet, .wsc, .ai, .wpt, .p7c, .fsh, .apk, .wmd, .yml, .menu, .lvl, .css, .raw, .yal, .ysp, .fos, .raf, .wpa, .wsh, .hplg, .x3f, .mp4, .wri, .mov, .sr2, .blob, .xll, .ltx, .zw, .dbf, .m4a, .zif, .snx, .sum, .sql, .iwd, .crw, .mcmeta, .vfs0, .zip, .hvpl, .wn, .mrwref, .wotreplay, .ncf, .vpk, .xx, .wpw, .jpe, .x3f, .3ds, .xmmap, .sidn, .ntl, .wm, .odc, .ppt, .xld, .csv, .1st, .wpd, .wbz, .wdp, .t12, .xwp, .pptm, .itdb, .fpk, .xlsx, .wbk, .dmp, .3fr, .wmo, .slm, .xlsx, .ws, .tor, .ibank, .accdb, .mlx, .iwi, .der, .docm, .vdf, .vcf, .wpb, .pem, .wbc, .mdf, .dng, .srw, .webp, .p12, .bkf, .xmind, .mdb, .lrf, .r3d, .pst, .pfx, .wp7, .crt, .png, .nrw, .zi, .xar, .txt, .cfr, .esm, .x, .epk, .ybk, .webdoc, .zdb, .kf, .arch00, .wps, .cer, .bar, .cdr, .psk, .asset, .sis, .re4, .itl, .bay, .ods, .upk, .rwl
Each encrypted file receives a new name, the Mmuz virus appends the extension ‘.mmuz’ at the end of the file name. Thus, if the file was called ‘image.jpg’ before encryption, then after it is encrypted it will be called ‘image.jpg.mmuz’. In each folder where the virus encrypted one or more files, it drops a file with the name ‘_readme.txt’.
This file is a ransom demand message. In this message, the authors of the Mmuz virus report that the victim’s files were encrypted and if the victim wants to decrypt them, then he needs to purchase a decryptor and a key. Attackers demand to pay them $980, if the victim is ready to pay the ransom within 72 hours, then the size of the ransom is halved to $490. Criminals offer the victim to decrypt one small file for free to confirm the possibility of decrypting .mmuz files. Obviously, if the criminals were able to decrypt one file, then this does not guarantee that after receiving the ransom they will give the victim the key and the decryptor.
Text presented in “_readme.txt” file:
Don’t worry, you can return all your files!
All your files like pictures, 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:
The message left by the Mmuz creators says that files cannot be decrypted without a key and a decryptor. Unfortunately, security researchers confirm that a decryptor and a unique key are required to decrypt files. As we reported above, fortunately there is a free decryptor. Mmuz File Decrypt tool can decrypt .mmuz files that were encrypted with an offline key. If the files were encrypted with an online key, then they cannot be decrypted, but there are several methods that can help recover encrypted files.
|Name||Mmuz ransomware, Mmuz file virus|
|Type||Ransomware, Filecoder, File locker, Crypto malware, Crypto virus|
|Ransom amount||$980/$490 in Bitcoins|
|Detection Names||FileRepMalware [Ransom], Trojan-Ransom.StopCrypt, Win32.Trojan.Kryptik.jm, Win.Dropper.Generickdz-9939781-0, UDS:Trojan-Ransom.Win32.Stop, BehavesLike.Win32.Corrupt.cc, ML/PE-A + Troj/Krypt-FV, Trojan.Win32.Save.a, Ransom:Win32/Filecoder.GF!MTB|
|Symptoms||Cannot open files stored on the computer. Your files now have a odd extension. Files called like ‘_readme.txt’, ‘#_README_#’, ‘_DECRYPT_’ or ‘recover’ in each folder with at least one encrypted file. Desktop background is changed to the ransom note.|
|Distribution ways||Unsolicited emails that are used to deliver malicious software. Exploit kits (cybercriminals use crypto virus packaged in an ‘exploit kit’ that can find a vulnerability in MS Windows OS, PDF reader, Adobe Flash Player, Browser). Social media, like web-based instant messaging programs. Remote desktop protocol (RDP) hacking.|
|Removal||Mmuz ransomware removal guide|
|Decryption||Mmuz File Decrypt Tool|
According to the security researchers, the Mmuz ransomware uses a strong encryption algorithm and therefore it is impossible to decrypt .mmuz files without a key. Fortunately, there is a Mmuz File Decrypt Tool that can decrypt files, but only if the files are encrypted with an offline key and the key itself has already been found. Moreover, our team has developed several methods, each of which gives a chance to restore the contents of encrypted files. In order not to miss any important part of this manual, we recommend that you open it in your smartphone or bookmark this page.
How to remove Mmuz virus (ransomware)
You need to remove Mmuz virus related files and registry entries before proceeding to decrypt or restore encrypted files. This must be done since otherwise the ransomware may re-encrypt the restored files. You can stop the ransomware from working, as it is not difficult to do. Another option is to perform a full system scan using free malware removal tools capable of detecting and removing ransomware infection.
It is very important to scan the computer for malware, as security researchers found that spyware could be installed on the infected computer along with the Mmuz ransomware. Spyware is a very dangerous security threat as it is designed to steal the user’s personal information such as passwords, logins, contact details, etc. If you have any difficulty removing the Mmuz virus, then let us know in the comments, we will try to help you.
To remove Mmuz ransomware, follow the steps below:
Kill Mmuz virus
Press CTRL, ALT, DEL keys together.
Click Task Manager. Select the “Processes” tab, look for something suspicious that is the Mmuz virus then right-click it and select “End Task” or “End Process” option. If your Task Manager does not open or the Windows reports “Task manager has been disabled by your administrator”, then follow the guide: How to Fix Task manager has been disabled by your administrator.
It is not difficult to detect a process related to the Mmuz ransomware. When looking for a malicious process, pay attention to the process icon and its name. Most often, this ransomware has a process name in the following format: 4-characters.tmp.exe or 4-characters.exe. For example: 7533.tmp.exe, A4b1.exe, CD15.tmp.exe, 19b2.exe. The process name can also contain “(32 bit)”. If you do not find a process with a similar name in the list of processes, then most likely the Mmuz ransomware has finished working. But keep in mind, if you do not remove the ransomware autostart entries, as demonstrated below, and do not delete its file, then after a while it may start again, and if it finds unencrypted files, immediately encrypt them.
Disable Mmuz startup
Select the “Start-Up” tab, look for something similar to the one shown in the example below, right click to it and select Disable.
Close Task Manager.
Delete Mmuz task
Type “Task Scheduler” in the search bar. Click Task Scheduler app in the search results. Click “Task Scheduler Library” in the left panel. On the right panel, right-click to “Time Trigger Task” and select Delete.
Close Task Scheduler.
Remove Mmuz virus
Run Task Manager and select the “Start-Up” tab. Right click to the Mmuz Start-Up entry and select Open File Location as shown below.
A directory containing one file will open in front of you, this file is the Mmuz virus. It needs to be removed. If you try to delete it immediately, then you will not succeed, since this file is protected from deletion.
To remove Mmuz virus, you need to do the following. Right-click on this file, select Properties. In the window that opens, select Security tab. Next, click the Advanced button below. A window will open as shown in the following example.
Click Disable inheritance. In the Block inheritance dialog box that opens, select the first item (Convert inherited permissions…) as shown below.
In the Permission entries list, select “Deny Everyone”, click Remove button and then OK. Close the file properties window. You should now be able to remove the Mmuz virus. Right-click on the file and select Delete.
Scan computer for malware
Zemana Anti Malware (ZAM) is a complete package of anti-malware utilities that can help you remove Mmuz virus. Despite so many features, it does not reduce the performance of your PC. This tool is able to remove almost all the types of security threats including ransomware, trojans, worms, adware, browser hijackers, potentially unwanted programs and other malicious software. Zemana has real-time protection that can defeat most malware and ransomware. You can run ZAM with any other antivirus without any conflicts.
First, visit the following page, then press the ‘Download’ button in order to download the latest version of Zemana AntiMalware.
Author: Zemana Ltd
Category: Security tools
Update: July 16, 2019
Once downloading is done, close all programs and windows on your personal computer. Double-click the install file named Zemana.AntiMalware.Setup. If the “User Account Control” prompt pops up similar to the one below, click the “Yes” button.
It will open the “Setup wizard” that will help you install Zemana AntiMalware on your computer. Follow the prompts and don’t make any changes to default settings.
Once install is finished successfully, Zemana will automatically start and you can see its main screen as on the image below.
Now press the “Scan” button to detect the Mmuz virus, other kinds of potential threats such as malware and trojans. A system scan can take anywhere from 5 to 30 minutes, depending on your PC. When a threat is found, the number of the security threats will change accordingly.
Once Zemana has completed scanning, a list of all items found is produced. Review the scan results and then click “Next” button. The Zemana Anti Malware will delete Mmuz ransomware related folders,files and registry keys and move the selected items to the program’s quarantine. When finished, you may be prompted to reboot the PC system.
In order to be 100% sure that the computer no longer has the Mmuz ransomware virus, we recommend using the Kaspersky virus removal tool (KVRT). This utility, as its name suggests, is developed by the Kaspersky lab and uses the core of the Kaspersky Antivirus. Unlike the Kaspersky Antivirus, KVRT has a smaller size and, most importantly, it can work together with an already installed anti-virus. This tool has great capabilities and therefore we suggest using KVRT in the last turn to be sure that the Mmuz crypto malware has been removed.
Download Kaspersky virus removal tool (KVRT) from the link below.
Author: Kaspersky® lab
Category: Security tools
Update: March 5, 2018
After the download is complete, double-click on the KVRT icon. Once initialization procedure is finished, you’ll see the Kaspersky virus removal tool screen as shown on the image below.
Click Change Parameters and set a check near all your drives. Click OK to close the Parameters window. Next press Start scan button to start checking your PC for the Mmuz ransomware and other known infections. When a threat is found, the number of the security threats will change accordingly.
Once the system scan is finished, KVRT will create a list of malicious software as displayed on the screen below.
All detected threats will be marked. You can delete them all by simply click on Continue to start a cleaning procedure.
How to decrypt .mmuz files
Files with the .mmuz extension are encrypted and to decrypt them you must use a decryptor and a unique key. You cannot unlock these files simply by deleting the new extension or changing their file name. Fortunately, there is a free Mmuz File Decrypt tool that can decrypt .mmuz files.
To decrypt .mmuz files, use “Mmuz File Decrypt tool”
- Download Free Mmuz File Decrypt tool from the following link.
STOP Djvu decryptor
- Scroll down to ‘New Djvu ransomware’ section.
- Click the download link and save the decrypt_STOPDjvu.exe file to your desktop.
- Run decrypt_STOPDjvu.exe, read the license terms and instructions.
- On the ‘Decryptor’ tab, using the ‘Add a folder’ button, add the directory or disk where the encrypted files are located.
- Click the ‘Decrypt’ button.
Mmuz File Decrypt Tool is a free software that can decrypt the encrypted files only in some cases, when the files were encrypted with an ‘offline key’. If the files were encrypted with an ‘online key’, then they cannot be decrypted. The reason for this is that the decryption key is in the hands of criminals and this key can not be determined. This does not mean that if your files are encrypted with an online key, then their contents are lost forever. Fortunately, there are several ways to recover encrypted files. These methods do not involve the use of decryption and therefore can be used in any case, no matter what key the ransomware used to encrypt files.
How to find out which key was used to encrypt files
Since Mmuz File Decrypt Tool only decrypts files encrypted with an offline key, each Mmuz’s victim needs to find out which key was used to encrypt the files. Determining the type of key used is not difficult. Below we give two ways. Use any of them.
Find out the type of key using ‘_readme.txt’ file
- Open the ransom demand message (‘_readme.txt’ file).
- Scroll down to the end of the file.
- There you will see a line with the text ‘Your personal ID’.
- Below is a line of characters that starts with ‘0428’ – this is your personal id.
Find out the type of key using ‘PersonalID.txt’ file
- Open disk C.
- Open directory ‘SystemID’.
- Open file named ‘PersonalID.txt’. This file lists ‘Personal ID’s that match the keys that the virus used to encrypt files.
The ‘Personal ID’ is not a key, it is an identifier related to a key that was used to encrypt files. If the ID ends with ‘t1’, then the files are encrypted with an offline key. If the ID does not end with ‘t1’, Mmuz virus used an online key. If you could not figure out how to determine which key was used to encrypt files, then we can help. Just write a request here or in the comments below.
Mmuz File Decrypt Tool : “No key for New Variant online ID”
If, when you try to decrypt .mmuz files, Mmuz File Decrypt Tool reports:
No key for New Variant online ID: *
Notice: this ID appears to be an online ID, decryption is impossible
It means that your files are encrypted with an ‘online key’ and their decryption is impossible, since only the Mmuz authors have the key necessary for decryption. In this case, you need to use alternative methods listed below to restore the contents of encrypted files.
Mmuz File Decrypt Tool : “No key for New Variant offline ID”
If, during decryption of .mmuz files, Mmuz File Decrypt Tool reports:
No key for New Variant offline ID: *t1
Notice: this ID appears be an offline ID, decryption MAY be possible in the future.
It means the following: your files are encrypted with an ‘offline key’, but the key itself has not yet been obtained by security researchers, in this case, you need to be patient and wait a while, in addition, you can also use alternative ways for recovering encrypted data.
If for some reason you were unable to decrypt the encrypted files, then We recommend to follow the news on our Facebook or YouTube channels. So you ‘ll know right away that it ‘s possible to decrypt .mmuz files.
This video step-by-step guide will demonstrate How to remove Mmuz virus, Decrypt/Recover .mmuz files.
How to restore .mmuz files
Fortunately, there are several simple ways that give everyone a chance to recover the contents of encrypted files. The methods presented below can help in cases when a free decryptor cannot decrypt .mmuz files or when files are encrypted with an online key. Alternative methods of file recovery do not use decryption, so there is no need for a key and decryptor. Before you begin, you must be 100% sure that the computer does not have active ransomware. Therefore, if you have not yet checked your computer for ransomware, do it now, use free malware removal tools or return to step 1 above.
Recover .mmuz files with ShadowExplorer
Now proceed to recover .mmuz files. We hope you have already completed all the steps that we discussed above. First of all, try to recover encrypted files using a free tool called ShadowExplorer. This program will allow you to recover your files from Shadow Volume Copies. These copies are created automatically by the Windows OS when you work with your files.
Unfortunately, Mmuz virus can automatically delete these copies and thus prevent you from recovering your files. Nevertheless, in some cases, the ransomware cannot delete all copies, and the user gets the opportunity to quickly restore all files. Therefore, you should definitely try this method!
First, please go to the following link, then click the ‘Download’ button in order to download the latest version of ShadowExplorer.
Category: Security tools
Update: September 15, 2019
After downloading is done, extract the saved file to a directory on your device. This will create the necessary files as shown on the screen below.
Start the ShadowExplorerPortable program. Now select the date (2) that you wish to recover from and the drive (1) you wish to restore files (folders) from as shown in the following example.
On right panel navigate to the file (folder) you wish to restore. Right-click to the file or folder and click the Export button like the one below.
And finally, specify a folder (your Desktop) to save the shadow copy of encrypted file and click ‘OK’ button.
This video step-by-step guide will demonstrate How to recover encrypted files using Shadow Explorer.
Restore .mmuz files using PhotoRec to
Another really working way to recover .mmuz files is to use a free tool named PhotoRec. It is created to recover deleted or lost files. Does the Mmuz ransomware block this method? Fortunately, the ransomware cannot block this method of recovering the contents of encrypted files. The more you used (moved, deleted, modified) files before infection, the greater the chance that you will be able to recover them.
Download PhotoRec on your MS Windows Desktop by clicking on the following link.
Category: Security tools
Update: March 1, 2018
Once downloading is finished, open a directory in which you saved it. Right click to testdisk-7.0.win and choose Extract all. Follow the prompts. Next please open the testdisk-7.0 folder as shown in the figure below.
Double click on qphotorec_win to run PhotoRec for Microsoft Windows. It’ll show a screen as shown below.
Select a drive to recover as on the image below.
You will see a list of available partitions. Select a partition that holds encrypted files as shown below.
Click File Formats button and specify file types to recover. You can to enable or disable the restore of certain file types. When this is complete, click OK button.
Next, press Browse button to select where restored files should be written, then press Search. We strongly recommend that you save the recovered files to an external drive.
Count of restored files is updated in real time. All recovered personal files are written in a folder that you have selected on the previous step. You can to access the files even if the recovery process is not finished.
When the restore is done, click on Quit button. Next, open the directory where recovered photos, documents and music are stored. You will see a contents as displayed below.
All recovered personal files are written in recup_dir.1, recup_dir.2 … sub-directories. If you are looking for a specific file, then you can to sort your recovered files by extension and/or date/time.
This video step-by-step guide will demonstrate How to recover encrypted files using PhotoRec.
How to protect your computer from Mmuz ransomware
Most antivirus programs already have built-in protection system against the ransomware virus. Therefore, if your personal computer does not have an antivirus program, make sure you install it. As an extra protection, run the HitmanPro.Alert. All-in-all, HitmanPro.Alert is a fantastic utility to protect your personal computer from any ransomware. If ransomware is detected, then HitmanPro.Alert automatically neutralizes malware and restores the encrypted files. HitmanPro.Alert is compatible with all versions of Windows operating system from MS Windows XP to Windows 10.
Please go to the link below to download HitmanPro Alert. Save it on your Windows desktop or in any other place.
Category: Security tools
Update: March 6, 2019
When downloading is finished, open the file location. You will see an icon like below.
Double click the HitmanPro Alert desktop icon. When the utility is opened, you will be displayed a window where you can select a level of protection, similar to the one below.
Now click the Install button to activate the protection.
To sum up
This guide was created to help all victims of the Mmuz ransomware virus. We tried to give answers to the following questions: how to remove ransomware; how to decrypt .mmuz files; how to recover encrypted files; what is an online key and what is an offline key. We hope that the information presented in this manual has helped you.
If you have questions, then write to us, leaving a comment below. If you need more help with Mmuz related issues, go to here.