How to remove Mpaj ransomware virus, Decrypt .mpaj files for free

What is Mpaj file extension

.Mpaj file extension is a filename extension that is used by the 219th version of the STOP ransomware to mark files that have been encrypted. This means that all files with this filename extension are encrypted by ransomware, which received the name ‘Mpaj ransomware’. Like other ransomware, it is created to encrypt the victim’s files, and then demand a ransom for decrypting them. Fortunately, a group of security researchers created a free Mpaj File Decrypt Tool. Mpaj File Decrypt Tool is a free decryptor that can help the ransomware victims decrypt .mpaj files. In addition to the decryptor, there are several more methods, each of which can help restore the contents of encrypted files. Read more about this, as well as how to remove Mpaj ransomware virus and protect your computer from such ransomware below.

Screenshot of files encrypted by Mpaj virus (‘.mpaj’ file extension)

What is Mpaj ransomware

Mpaj ransomware is a new malware that belongs to the STOP (Djvu) ransomware family. According to security researchers, this malware is not much different from previous variants of STOP ransomware, such as Jope and Mado that were discovered earlier. Like other variants of STOP ransomware, the Mpaj virus is distributed by websites offering to download torrents, cracked games, freeware, key generators, activators and so on.

Upon execution, the Mpaj ransomware creates a folder in the Windows system directory where it places a copy of itself and changes some Windows settings so that it starts up every time the computer is restarted or turned on. The virus collects information about the victim’s computer and then tries to establish a connection with its command server (C&C). If the connection has been established, then it sends information about the infected computer to the server, and in response receives the encryption key (the so-called ‘online key’) and additional commands and malware that must be executed on the victim’s computer. If the Mpaj ransomware could not establish a connection with its command server, then it uses a fixed key (the so-called ‘offline key’).

The Mpaj ransomware encrypts files using a strong encryption algorithm and a long key (‘offline key’ or ‘online key’, as described above). The virus tries to encrypt as many files as possible, for this it only encrypts the first 154kb of the contents of each file and thus significantly speeds up the encryption process. The Mpaj ransomware has the ability to encrypt files on all drives connected to the computer: internal hard drives, flash USB disks, network storage, and so on. It skips without encryption: files located in the Windows system directories, files with the extension .dll, .lnk, .ini, .bat, .sys and files with the name ‘_readme.txt’. The remaining files located on the victim’s computer can be encrypted. For example, the following file types may be the target of ransomware attack:

.crt, .sidn, .vpp_pc, .yal, .indd, .desc, .z, .iwi, .bkf, .arch00, .litemod, .wp6, .kf, .jpeg, .docx, .pptm, .odb, .css, .vtf, .ybk, .pdf, .x, .forge, .mef, .big, .js, .gho, .xls, .tax, .bar, .dwg, .mddata, .xlgc, .psd, .wgz, .png, .zi, .csv, .xx, .hplg, .pkpass, .xlsm, .raw, .mrwref, .wp7, .esm, .snx, .rar, .pst, .wn, .wma, .wps, .sql, .wmv, .xdl, .m4a, .p7c, .sid, .cas, .sie, .zip, .itdb, .srw, .xls, .wpd, .wpt, .xlsm, .re4, .cr2, .sis, .qdf, .itl, .wpg, .mdf, .erf, wallet, .webdoc, .rwl, .dazip, .map, .zw, .sav, .vcf, .bkp, .cfr, .3ds, .wmf, .ods, .wp5, .odp, .gdb, .1, .epk, .dbf, .nrw, .avi, .3fr, .wri, .xmmap, .wsc, .sr2, .wbz, .7z, .mp4, .xyw, .der, .rofl, .sum, .zif, .ztmp, .wdp, .wpe, .tor, .accdb, .wmv, .xxx, .wsd, .hkdb, .xlk, .ltx, .webp, .asset, .wpa, .yml, .wmo, .xyp, .wm, .bc7, .bik, .sidd, .w3x, .apk, .pak, .crw, .dng, .wbm, .vfs0, .wcf, .2bp, .srf, .docm, .ai, .svg, .xbdoc, .wire, .wb2, .fsh, .wpd, .mlx, .bay, .wbc, .arw, .zip, .qic, .wbk, .iwd, .pem, .hvpl, .xbplate, .pef, .wsh, .t12, .m2, .xf, .zdb, .jpe, .wot, .upk, .ysp, .db0, .itm, .m3u, .d3dbsp, .ncf, .xwp, .x3d, .wp4, .xmind, .mpqge, .dcr, .pfx, .dxg, .mdb, .vpk, .lrf, .psk, .icxs, .xar, .ptx, .kdc, .xy3, .txt, .sb, .1st, .syncdb, .raf, .rgss3a, .xml, .wbd, .wotreplay, .wav, .0, .wma, .ff, .fos, .y, .py, .blob, .kdb, .dmp, .xlsb, .bc6, .x3f, .r3d, .mdbackup, .odm, .ibank, .ws, .dba, .ppt, .p12, .fpk, .zdc, .xld, .rtf, .xlsx, .odc, .wpb, .bsa, .orf, .wpw, .jpg, .x3f, .lbf, .slm, .wdb, .das, .t13, .wbmp, .wpl, .rw2, .cdr, .ntl, .cer, .mcmeta, .lvl, .flv, .pdd, .doc, .rim, .zabw, .z3d, .eps, .pptx, .xdb, .vdf, .rb, .odt, .layout, .p7b, .menu, .wp, .wps, .xll, .xpm, .hkx

The Mpaj ransomware encrypts file-by-file. Each file that has been encrypted will be renamed, the .mpaj extension will be added at the end of its name. This means the following. If the file had the name ‘mydocument.docx’, then after the virus encrypts it, this file will have the name ‘mydocument.docx.mpaj’. In every directory where there is at least one encrypted file, the virus places a file named ‘_readme.txt’. The file contains a message from Mpaj authors. An example of the contents of this file is given below.

Screenshot of the contents of ‘_readme.txt’ file (Mpaj ransom note)

This message says that all files on the computer are encrypted and the only way to decrypt them is to buy a key and a decryptor from the Mpaj ransomware authors. That is, criminals demand a ransom for unlocking the victim’s files. The size of the ransom is $980, but if the victim is ready to pay the ransom within 72 hours, then its size is halved to $490. Attackers offer victims to verify that encrypted files can be decrypted. To do this, the victim must send them a small file to one of the email addresses specified in the ‘_readme.txt’ file. Of course, it is obvious that a single decrypted file cannot guarantee that after paying the ransom, the criminals will provide the victim with a working key and decryptor.

Threat Summary

How to remove Mpaj ransomware, Recover, Decrypt .mpaj files

Security researchers confirm the words of the authors of Mpaj virus. All files with the extension ‘.Mpaj’ are encrypted and thus cannot be read and used. The only way to decrypt them is to use the key and the decryptor. Fortunately, there is some good news. As we already reported above, the Mpaj virus belongs to STOP ransomware family, which means that you can use the free decryptor created by Emsisoft to decrypt the encrypted files. Even if the decryptor does not help, there are some alternative ways that can help restore the contents of the encrypted files. To learn more about decrypting files, simply scroll down to section ‘How to decrypt .mpaj files’. 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.

1. How to remove Mpaj ransomware virus
2. How to decrypt .mpaj files
3. How to restore .mpaj files
4. How to protect your personal computer from Mpaj ransomware

How to remove Mpaj ransomware virus

Finding and removing the Mpaj ransomware components manually is very difficult, so we recommend using free malware removal tools. Moreover, it is desirable to use not one, but several utilities. Even if it seems to you that there is no ransomware on the computer, it does not mean anything. The virus may start encrypting the files again the next time you turn on or restart the computer. You must be completely sure that Mpaj has been removed, and also that there is no other malware on the computer. Below we provide a list of recommended tools with brief instructions.

Remove Mpaj ransomware with Zemana AntiMalware (ZAM)

Zemana AntiMalware is a malware removal tool that is one of the best in its class. It can scan for and remove a large number of of different security threats, including trojans, adware, worms, spyware, ransomware and malicious software that masqueraded as legitimate computer programs. Also Zemana Anti Malware includes another tool called FRST – is a helpful program for manual removal of files and parts of the Windows registry created by crypto malware.

Click the link below to download Zemana Anti-Malware (ZAM). Save it directly to your Microsoft Windows Desktop.

Zemana AntiMalware
164030 downloads
Author: Zemana Ltd
Category: Security tools
Update: July 16, 2019

After downloading is done, close all windows on your computer. Further, launch the install file named Zemana.AntiMalware.Setup. If the “User Account Control” prompt pops up as shown on the screen below, click the “Yes” button.

It will display the “Setup wizard” that will help you install Zemana on the system. Follow the prompts and do not make any changes to default settings.

Once install is complete successfully, Zemana will automatically run and you can see its main window like below.

Next, click the “Scan” button to begin checking your computer for the Mpaj ransomware virus, other malware, worms and trojans. A scan may take anywhere from 10 to 30 minutes, depending on the number of files on your personal computer and the speed of your system. While the Zemana Anti Malware (ZAM) is checking, you may see how many objects it has identified either as being malware.

Once Zemana AntiMalware (ZAM) completes the scan, Zemana will produce a list of unwanted apps and ransomware virus. You may delete threats (move to Quarantine) by simply press “Next” button.

The Zemana Free will remove Mpaj crypto virus related folders,files and registry keys and add threats to the Quarantine. When disinfection is finished, you can be prompted to restart your computer.

Remove Mpaj virus with MalwareBytes

If you are having problems with the Mpaj virus removal, then download MalwareBytes Anti-Malware. It’s free for home use, and finds and removes various unwanted apps that attacks your PC or degrades computer performance. MalwareBytes Free can uninstall adware, PUPs as well as malware, including ransomware and trojans.

1. First, visit the following page, then click the ‘Download’ button in order to download the latest version of MalwareBytes Anti Malware (MBAM).
   
   

   Malwarebytes Anti-malware
   326382 downloads
   Author: Malwarebytes
   Category: Security tools
   Update: April 15, 2020
   
2. At the download page, click on the Download button. Your web-browser will display the “Save as” dialog box. Please save it onto your Windows desktop.
3. After the download is complete, please close all apps and open windows on your computer. Double-click on the icon that’s named mb3-setup.
4. This will run the “Setup wizard” of MalwareBytes Free onto your PC. Follow the prompts and don’t make any changes to default settings.
5. When the Setup wizard has finished installing, the MalwareBytes Anti Malware (MBAM) will start and display the main window.
6. Further, click the “Scan Now” button to perform a system scan with this tool for the Mpaj crypto virus, other malware, worms and trojans. A system scan may take anywhere from 5 to 30 minutes, depending on your PC. While the MalwareBytes Anti-Malware is scanning, you may see how many objects it has identified either as being malicious software.
7. When MalwareBytes is done scanning your machine, MalwareBytes Free will show a list of all threats detected by the scan.
8. Once you have selected what you want to remove from your computer press the “Quarantine Selected” button. When that process is finished, you may be prompted to reboot the PC.
9. Close the AntiMalware and continue with the next step.

Video instruction, which reveals in detail the steps above.

Use KVRT to remove Mpaj

Kaspersky virus removal tool (KVRT) is free and easy to use. It can scan and remove ransomware, spyware, PUPs, worms, trojans, adware and other malware. KVRT is powerful enough to find and delete malicious registry entries and files that are hidden on the system.

Download Kaspersky virus removal tool (KVRT) on your PC system by clicking on the following link.

Kaspersky virus removal tool
129055 downloads
Author: Kaspersky® lab
Category: Security tools
Update: March 5, 2018

When the download is complete, double-click on the KVRT icon. Once initialization process is complete, you’ll see the KVRT screen like the one below.

Click Change Parameters and set a check near all your drives. Click OK to close the Parameters window. Next press Start scan button for checking your machine for the Mpaj ransomware . A scan can take anywhere from 10 to 30 minutes, depending on the number of files on your system and the speed of your computer. When a threat is found, the number of the security threats will change accordingly. Wait until the the scanning is complete.

Once finished, the results are displayed in the scan report as shown in the figure below.

You may remove threats (move to Quarantine) by simply click on Continue to start a cleaning task.

How to decrypt .mpaj files using Mpaj File Decrypt Tool

As we already reported above, files with .mpaj extension are files that have been encrypted by the Mpaj ransomware virus. Their contents will remain locked until decrypted using the decryptor and the key. Fortunately, there is a free Mpaj File Decrypt Tool that can decrypt .mpaj files. Below we provide instructions on where to download and how to use this decryptor.

Mpaj File Decrypt Tool (STOP Djvu decryptor)

To decrypt .mpaj files, use free Mpaj File Decrypt Tool

• Download Mpaj 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.

Unfortunately, at the moment, the Mpaj File Decrypt Tool is able to decrypt .mpaj files encrypted with an offline key, as Emsisoft found a way to identify this key. 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 find this key. Of course, the Mpaj ransomware authors own this key, but we do not think that paying a ransom is the right way to decrypt .mpaj 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

Since Mpaj File Decrypt Tool only decrypts files encrypted with the offline key, each virus 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.

Personal ID is highlighted here

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 ‘0219’ – 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’, the Mpaj 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.

Mpaj File Decrypt Tool : No key for New Variant offline ID

If during decryption of .mpaj files the Mpaj File Decrypt Tool reports No key for New Variant offline ID, then this means the following: your files are encrypted with an ‘offline key’, but the key itself has not yet been found 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. It is impossible to say exactly when the ‘offline key’ will be determined. Sometimes it takes several days, sometimes more. We recommend that you try to decrypt .mpaj files from time to time. You can also use alternative ways listed below for recovering encrypted data.

Mpaj File Decrypt Tool : No key for New Variant online ID

If, when you try to decrypt .mpaj files, the Mpaj File Decrypt Tool reports No key for New Variant online ID, then this means that your files are encrypted with an ‘online key’ and their decryption is impossible, since only the Mpaj 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.

How to restore .mpaj files

As we mentioned above, in addition to using the Mpaj File Decrypt Tool, there are several more methods for recovering encrypted files. These methods do not require the use of a decryptor and a key, and therefore are suitable for all cases when the virus used an online key, and for the case when the virus used an offline key. It is very important to check your computer for malware before you try to recover encrypted files. You must be 100% sure that the Mpaj ransomware virus is completely removed. To scan your computer for ransomware, use free malware removal tools.

Use shadow copies to restore .mpaj files

The Microsoft Windows has a feature called ‘Shadow Volume Copies’ that can help you to recover .mpaj files encrypted by the ransomware. A small tool called ShadowExplorer will allow you to easily access the Shadow copies and restore the encrypted files to their original state. Unfortunately, the ransomware can delete these Shadow copies before it starts encrypting files. Therefore, if ShadowExplorer did not help you, then try another method, which is given below.

Download ShadowExplorer by clicking on the link below. Save it on your Desktop.

ShadowExplorer
438663 downloads
Author: ShadowExplorer.com
Category: Security tools
Update: September 15, 2019

After downloading is complete, extract the saved file to a folder on your personal computer. This will create the necessary files as shown on the image below.

Launch the ShadowExplorerPortable program. Now choose the date (2) that you want to recover from and the drive (1) you want to recover files (folders) from as on the image below.

On right panel navigate to the file (folder) you want to restore. Right-click to the file or folder and click the Export button like 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.

Run PhotoRec to recover .mpaj files

The last chance to restore .mpaj files to their original state is using data recovery tools. We recommend a program called PhotoRec. It has all the necessary functions to restore the contents of encrypted files. It helped many victims recover data when it seemed like there was no more hope.

Download PhotoRec by clicking on the link below. Save it on your Windows desktop or in any other place.

PhotoRec
220572 downloads
Author: CGSecurity
Category: Security tools
Update: March 1, 2018

When the downloading process is done, open a directory in which you saved it. Right click to testdisk-7.0.win and select Extract all. Follow the prompts. Next please open the testdisk-7.0 folder like below.

Double click on qphotorec_win to run PhotoRec for Windows. It will show a screen as shown in the figure below.

Choose a drive to recover as displayed on the screen below.

You will see a list of available partitions. Choose a partition that holds encrypted photos, documents and music like the one below.

Press 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, press Browse button to select where recovered photos, documents and music should be written, then click Search.

Count of restored files is updated in real time. All restored personal files are written in a folder that you have chosen on the previous step. You can to access the files even if the restore process is not finished.

When the restore is finished, press on Quit button. Next, open the directory where restored documents, photos and music are stored. You will see a contents as displayed below.

All recovered files are written in recup_dir.1, recup_dir.2 … sub-directories. If you are searching 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 personal computer from Mpaj ransomware

Most antivirus programs 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, use the HitmanPro.Alert. HitmanPro.Alert is a small security tool. 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.

Please go to the following link to download the latest version of HitmanPro Alert for Windows. Save it to your Desktop.

HitmanPro.Alert
6826 downloads
Author: Sophos
Category: Security tools
Update: March 6, 2019

After the download is finished, open the folder in which you saved it. You will see an icon like below.

Double click the HitmanPro Alert desktop icon. When the tool is launched, you will be shown a window where you can select a level of protection, as displayed on the image below.

Now click the Install button to activate the protection.

To sum up

This guide was created to help all victims of the Mpaj ransomware virus. We tried to give answers to the following questions: how to remove ransomware; how to decrypt .mpaj files; how to recover files, if the Mpaj File Decrypt Tool does not help; 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 Mpaj related issues, go to here.