What is Mmdt virus?
Mmdt virus is a ransomware that belongs to the ransomware family called STOP (Djvu). Ransomware is a form of malware that encrypts the victim’s files and demands a ransom for decrypting them. The Mmdt virus encrypts files, renames them by appending the .mmdt extension, and creates files named “_readme.txt” containing the ransom demand message. For example, a file named “image.jpg” will be renamed to “image.jpg.mmdt”, a “document.docx” file to “document.docx.mmdt”, “invoice.pdf” to “invoice.pdf.mmdt”, and so on.
- What is Mmdt virus?
- Remove Mmdt virus (ransomware)
- Decrypt .mmdt files
- Restore .mmdt files
- Video Guide
Mmdt ransomware is a variant of the STOP (Djvu) ransomware. It is designed to encrypt files located on the victim’s computer, and then extort money to decrypt them. Mmdt virus sneaks into the system without any visible symptoms, which is why users notice that their computer is infected too late, when the files are already encrypted. Typically, ransomware like Mmdt can infect a computer when a user runs and installs the infected program as well as cracked games, freeware, key generators and other similar software.
Upon execution, the ransomware creates a directory in the Windows system directory, copies itself to this directory, changes some OS settings, and also collects information about the infected computer. After that, Mmdt virus tries to connect to its command server. If this succeeds, the ransomware sends data about the infected computer to the server, and from it receives a key (so-called ‘online key’) necessary for file encryption. If the connection to its command server has not been established, then the ransomware uses a fixed key (so-called ‘offline key’). The main difference between an online key and an offline key is that the online key is in the hands of criminals and cannot be determined. The offline key is fixed and can be determined by security researchers. This gives hope that victims of Mmdt virus will be able to decrypt files without paying ransom.
A file with extension ‘.mmdt’ is a file that has been encrypted by the Mmdt ransomware and therefore the contents of this file are locked. Each file that has been affected by the virus is renamed in such a way that the ‘.mmdt’ extension is appended to its old name on the right. This means the following, if the file was named ‘document.docx’, then after it is encrypted, it will be called ‘document.docx.mmdt’. Each file on the victim’s computer becomes the target of Mmdt virus. No matter where the file is located, on the internal drive or network storage, this file will be encrypted. The virus only does not encrypt files in the OS system directories, files with the extension .dll, .lnk, .bat, ini, .sys and files named ‘_readme.txt’. Thus, the following types of files can be encrypted:
.wmf, .wma, .arch00, .pdf, .z, .sidd, .bkf, .2bp, .mcmeta, .zip, .epk, .gdb, .1st, .ppt, .wbc, .png, .docm, .wpl, .rw2, .wdb, .xll, .mdbackup, .bsa, .p7b, .xx, .wgz, .wps, .bkp, .hkx, .py, .orf, .rar, .wbz, .flv, .crw, .jpe, .xlsx, .blob, .hplg, .3fr, .dcr, .wpd, .mrwref, .hkdb, .xpm, .pem, .vpk, .wm, .sb, .xyw, .sis, .dwg, .sav, .odt, .pst, .xmind, .wp4, .wn, .rwl, .map, .7z, .sum, .wpd, .icxs, .hvpl, .psk, .wdp, .t13, .1, .bik, .gho, .zip, .xdl, .cr2, .xlsm, .kdc, .mddata, .pef, .apk, .layout, .wav, .docx, .wbd, .jpeg, .bar, .wpe, .wpa, .yal, .wpt, .wmv, .indd, .ods, .ff, .xml, .kdb, .wb2, .snx, .fsh, .xxx, .xlsx, .itl, .svg, .txt, .mpqge, .rtf, .vfs0, .wpb, .wot, .sid, .wma, .w3x, .xlgc, .big, .ltx, .ysp, .bc7, .cdr, .psd, .vpp_pc, .css, .xls, .vtf, .ai, .xls, .pfx, .slm, .pptx, .js, .zdb, .jpg, .wp, .desc, .x3f, .rofl, .wsc, .rgss3a, .pdd, .wsd, .qic, .zabw, .xlsm, .mdb, .m2, .dazip, .xwp, .wmd, .t12, .iwi, .x, .nrw, .zw, .xld, .crt, .ncf, .webp, .cfr, .accdb, .x3f, .rim, .bay, .sidn, .yml, .mdf, .menu, .y, .db0, .ntl, .upk, .srf, .syncdb, .sr2, .wotreplay, .vdf, .xmmap, .xf, .wps, .das, .qdf, .wsh, .der, .fos, .xyp, .tor, .mov, .wri, .wpg, .z3d, .dmp, .3ds, .litemod, .wcf, .mef, .vcf, .d3dbsp, .0, wallet, .ptx, .wp5, .tax, .esm, .lrf, .webdoc, .pak, .wbmp, .3dm, .kf, .odb, .wbm, .forge, .doc, .m3u, .lvl, .asset, .sql, .ybk, .itdb, .ws, .xlk, .sie, .eps, .iwd, .ztmp, .fpk, .xdb, .xar, .ibank, .re4, .p7c, .odp, .p12, .wp6, .bc6, .zif, .r3d
As we said, Mmdt file is an encrypted file. To decrypt it, you must use the key and the decryptor. This is reported by the authors of Mmdt virus, in a message that they leave on the infected computer. This message is in a file called ‘_readme.txt’. The criminals place such a file in every directory where there is at least one encrypted file. An example of the contents of this file is given below.
The contents of this file are a ransom demand message. Criminals report that all files on the computer are encrypted, and only the key and decryptor can decrypt these files and restore access to their contents. Attackers demand a ransom of $980 in exchange for a key and a decryptor. If the victim is ready to pay the ransom quickly, within 72 hours, the size of the ransom is halved to $490. The authors of the virus offer to decrypt one Mmdt file for free and thus prove the possibility that the files can be decrypted.
The full contents of the file ‘_readme.txt’:
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:
Security researchers confirm that .gyu files are encrypted and that a key and a decryptor are needed to decrypt these files. Fortunately, there is a free Mmdt File Decrypt Tool. It is a program that can decrypt .mmdt files. Unfortunately, this decryptor is limited in that it can only decrypt files encrypted with an offline key, files encrypted with an online key cannot yet be decrypted. The reason for this is that only the Mmdt creators have the online key and this key cannot be determined or cracked. In addition to using the Mmdt File Decrypt Tool, there are several other ways to restore the content of encrypted files.
The instructions below detail how to remove the Mmdt ransomware, decrypt .mmdt files, and how to recover encrypted files if the Mmdt file decryption tool was unable to decrypt them. Read the entire manual carefully. To make it easier for you to follow the instructions, we recommend that you print it or open it on your smartphone.
|Name||Mmdt ransomware, Mmdt File Virus|
|Type||File locker, Filecoder, Crypto malware, Crypto virus, Ransomware|
|Ransom amount||$490 or $980 in Bitcoins|
|Detection Names||CrypterX-gen [Trj], W32/GenKryptik.FBYO!tr, Trojan:Win32/Sabsik.FL.B!ml, ML/PE-A, BehavesLike.Win32.Generic.bc, Ransom.Win32.STOP.SMYXBFX.hp, Trojan.Malware.300983.susgen, W32.AIDetect.malware1|
|Symptoms||Your documents, photos and music fail to open. Your documents, photos and music have a wrong name, suffix or extension, or don’t look right when you open them. Files called such as ”, ‘READ-ME’, ‘_open me’, _DECRYPT YOUR FILES’ or ‘_Your files have been encrypted” in every folder with an encrypted file. New files on your desktop, with name variants of: ‘HOW_TO_DECRYPT.txt’, ‘DECRYPT.txt’ or ‘README.txt’.|
|Distribution methods||Malicious spam (also known as ‘malspam’). Drive-by downloading (when a user unknowingly visits an infected web-page and then malicious software is installed without the user’s knowledge). Social media, such as web-based instant messaging applications. USB keys containing malware.|
|Removal||Mmdt ransomware removal guide|
|Decryption||Mmdt File Decrypt Tool|
|Recovery||Mmdt File Recovery|
How to remove Mmdt ransomware virus
You need to remove the Mmdt ransomware virus and its autostart 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 Mmdt 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 Mmdt virus, then let us know in the comments, we will try to help you.
To remove Mmdt ransomware, follow the steps below:
Kill Mmdt ransomware
Press CTRL, ALT, DEL keys together.
Click Task Manager. Select the “Processes” tab, look for something suspicious that is the Mmdt ransomware 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 Mmdt 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 Mmdt 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 Mmdt Start-Up
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 Mmdt ransomware 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 Mmdt virus
Run Task Manager and select the “Start-Up” tab. Right click to the Mmdt ransomware 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 Mmdt 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 delete this file, you need to do the following. Right-click on the 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 Mmdt virus. Right-click on the file and select Delete.
Scan computer for malware
MalwareBytes Anti-Malware (MBAM) is an antimalware software that can help you remove Mmdt virus. MalwareBytes can be used to remove almost all the forms of malicious programs including ransomware, trojans, worms, adware, browser hijackers, potentially unwanted software and spyware. MalwareBytes has real-time protection that can defeat most malicious software and ransomware. Despite so many features, it does not reduce the performance of your computer. You can use MalwareBytes Anti-Malware with any other antivirus without any conflicts.
First, please go to the link below, then click the ‘Download’ button in order to download the latest version of MalwareBytes AntiMalware.
Category: Security tools
Update: April 15, 2020
When the downloading process is done, close all windows on your computer. Further, launch the file named MBSetup. If the “User Account Control” dialog box pops up like below, click the “Yes” button.
It will show the Setup wizard which will assist you install MalwareBytes on the computer. Follow the prompts and do not make any changes to default settings.
After the setup is complete successfully, press “Get Started” button. Then MalwareBytes AntiMalware will automatically run and you can see its main window such as the one below.
Next, click the “Scan” button for scanning your computer for the Mmdt ransomware and other security threats. A system scan can take anywhere from 5 to 30 minutes, depending on your computer. While the MalwareBytes program is scanning, you can see how many objects it has identified as threat.
When the scanning is done, the results are displayed in the scan report. In order to remove all threats, simply press “Quarantine” button.
The MalwareBytes Anti-Malware will remove Mmdt virus related folders,files and registry keys and move the selected threats to the program’s quarantine. Once that process is done, you can be prompted to reboot your computer.
In order to be 100% sure that the computer no longer has the Mmdt virus, we recommend using the Kaspersky virus removal tool (KVRT). This program is a free removal utility which can scan your PC for a wide range of security threats such as ransomware, adware, spyware, PUPs, trojans, worms as well as other malware. It will perform a deep scan of the device including hard drives and Windows registry. When a malicious software is found, it will help you to remove all detected threats from your personal computer by a simple click.
Download Kaspersky virus removal tool by clicking on the following link.
Author: Kaspersky® lab
Category: Security tools
Update: March 5, 2018
Once the downloading process is finished, double-click on the KVRT icon. Once initialization procedure is finished, you’ll see the KVRT screen like below.
Click Change Parameters and set a check near all your drives. Click OK to close the Parameters window. Next click Start scan button to perform a system scan for the Mmdt crypto malware and other known infections. This process may take some time, so please be patient.
After the scan get completed, Kaspersky virus removal tool will create a list of unwanted apps and ransomware virus as on the image below.
Review the results once the tool has finished the system scan. If you think an entry should not be quarantined, then uncheck it. Otherwise, simply click on Continue to begin a cleaning process.
How to decrypt .mmdt files
All files with .mmdt extension are encrypted and the only way to access their contents is to decrypt them. To decrypt .mmdt files, you need to use a unique key and decryptor. As we said above, Emsisoft company was able to create a decryptor and found a way in some cases to determine the key that was used to encrypt the files. It can help the ransomware victims to decrypt encrypted files for free.
To decrypt .mmdt files, use Mmdt File Decrypt Tool
- Download Mmdt 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.
Mmdt File Decrypt Tool is a free software that can decrypt files encrypted with an offline key. Unfortunately, files encrypted with an online key cannot yet be decrypted. The online key is unique to each infected computer, and at the moment there is no way to obtain this key. Of course, criminals have this key, but we do not think that paying a ransom is a way to decrypt .mmdt files. In the case when the files are encrypted with an online key, there is a chance to restore the encrypted files using alternative methods, which are described below.
How to find out which key was used to encrypt files
Below we show two ways to help you determine what type of key was used to encrypt the files. This is very important, since the type of key determines whether it is possible to decrypt .mmdt files for free. We recommend using the second method, as it is more accurate.
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, 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’, Mmdt ransomware 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.
Mmdt File Decrypt Tool : “No key for New Variant online ID”
If, when you try to decrypt .mmdt files, Mmdt 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 Mmdt 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.
Mmdt File Decrypt Tool : “No key for New Variant offline ID”
If, during decryption of .mmdt files, Mmdt 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 .mmdt files.
This video step-by-step guide will demonstrate How to use STOP Djvu decryptor to Decrypt encrypted files.
How to restore .mmdt files
If your files were encrypted with .mmdt extension, then there is a chance that you can recover the files without decryption. We recommend using PhotoRec and ShadowExplorer that are designed to find and recover lost and deleted data. Mostly such programs are paid, but these tools can restore your files for free. Each of these programs has already helped many victims to recover encrypted files in what would seem to be the most hopeless cases. We want to remind you that before you try to recover files, you need to scan your computer for ransomware using free malware removal tools. It is very important to find the Mmdt virus and completely remove it.
Use shadow copies to restore .mmdt files
There is one very useful feature in modern versions of Windows OS. Windows automatically makes copies of the files you use. These copies are called “volume shadow copies” and are not directly visible to the user. ShadowExplorer will allow you to easily access these files and thus restore the original state of the encrypted files. Of course, not everything is so simple, unfortunately, very often ransomware deletes these copies, thereby preventing easy recovery of encrypted files. But in some cases, hidden copies of files remain, which allows you to quickly restore encrypted files. Therefore, you should definitely try this method.
First, visit the following page, then press the ‘Download’ button in order to download the latest version of ShadowExplorer.
Category: Security tools
Update: September 15, 2019
When the download is finished, extract the saved file to a directory on your device. This will create the necessary files like below.
Launch the ShadowExplorerPortable application. Now select the date (2) that you wish to recover from and the drive (1) you want to restore files (folders) from as shown in the figure below.
On right panel navigate to the file (folder) you wish to restore. Right-click to the file or folder and click the Export button as shown on the screen below.
And finally, specify a directory (your Desktop) to save the shadow copy of encrypted file and press ‘OK’ button.
This video step-by-step guide will demonstrate How to recover encrypted files using Shadow Explorer.
Recover .mmdt files with PhotoRec
Another working way to recover .mmdt files is to use a tool that finds and recovers deleted files. We recommend using PhotoRec. This is one of the few programs that allows you to do this for free. The reason that you can recover encrypted files using this method is simple – when you or any program, including ransomware, deletes a file, this file is not deleted, Windows marks it as deleted and hides it. PhotoRec finds such deleted files and restores them. Thus, you receive files in an unencrypted state. The only thing I want to draw your attention to is that the less you use your computer after a ransomware infection, the better your chances of recovering encrypted files.
Download PhotoRec on your Desktop from the link below.
Category: Security tools
Update: March 1, 2018
When the download 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 on the screen below.
Double click on qphotorec_win to run PhotoRec for Windows. It’ll show a screen like below.
Select a drive to recover as displayed below.
You will see a list of available partitions. Select a partition that holds encrypted personal files as on the image below.
Click File Formats button and choose file types to restore. You can to enable or disable the restore of certain file types. When this is complete, click OK button.
Next, click Browse button to choose where recovered photos, documents and music 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 photos, documents and music 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 files are stored. You will see a contents like below.
All restored photos, documents and music are written in recup_dir.1, recup_dir.2 … sub-directories. If you’re looking for a specific file, then you can to sort your restored 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 PC from Mmdt ransomware
Most antivirus software already have built-in protection system against the crypto malware. Therefore, if your personal computer does not have an antivirus program, make sure you install it. As an extra protection, run the HitmanPro.Alert. HitmanPro.Alert is a small security utility. It can check the system integrity and alerts you when critical system functions are affected by malware. HitmanPro.Alert can detect, remove, and reverse ransomware effects.
Visit the following page to download the latest version of HitmanPro Alert for Windows. Save it directly to your Microsoft Windows Desktop.
Category: Security tools
Update: March 6, 2019
Once the download is done, open the file location. You will see an icon like below.
Double click the HitmanPro Alert desktop icon. When the utility is started, you’ll be displayed a window where you can select a level of protection, like below.
Now click the Install button to activate the protection.
This guide was created to help all victims of Mmdt ransomware virus. We tried to give answers to the following questions: how to remove ransomware; how to decrypt .mmdt 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 Mmdt related issues, go to here.