.Maas file extension ransomware (Maas File Recovery Guide)

What is Maas file extension

.Maas file extension is a file extension that is used by the newest version of widespread ransomware called STOP (Djvu) to mark files that have been encrypted. Maas ransomware was discovered by the security researchers recently. Upon infecting a computer, it encrypts files on the computer, renames the affected files, adding .Maas extension at the end of their filenames, and demands a ransom for a key that will allow the computer owner to decrypt the files. Fortunately, there is a free Maas File Decrypt Tool called ‘STOP (Djvu) Decryptor’ that allows in some cases to decrypt encrypted files. Scroll through this article below to learn more about this decrypt tool and how to use it, as well as alternative ways to recover the contents of encrypted files.

Screenshot of files encrypted by Maas ransomware virus (‘.maas’ file extension)

What is Maas ransomware virus

First discovered recently, Maas ransomware is the newest version of STOP ransomware. Ransomware is a type of malware that encrypts files on the victim’s computer and demands a ransom payment to restore access to the contents of these files. Maas targets users running Microsoft Windows. In most cases, this malware requires user actions in order to be installed on the computer. Typically, criminals use various tricks, for example, disguising the malicious software as a freeware, cracks, activators and key generators, so that victims download and run Maas virus on their computer.

Upon infecting a computer, the Maas ransomware performs the following steps as part of its preparation for encrypting files: creates a folder in the Windows system directory and copies itself to it; adds itself to the list of programs that start up every time the computer is turned on; collects information about the victim’s computer; establishes connection with its command server (C&C).

If Maas was able to establish a connection with the C&C server, then it sends some information about the victim’s computer to the server, and the server returns a key to it that must be used to encrypt files. Such a key is called ‘online key’ and it is unique for each case of ransomware infection. If a connection to the C&C server has not been established, the ransomware uses a fixed key (so called ‘offline key’), which is unique for each version of STOP (djvu) ransomware, but the same for each case of Maas infection.

Having determined which key to use, Maas ransomware virus goes to the main thing – it starts the file encryption process. Of course, it does not encrypt absolutely all files, since encryption of the Windows system files will cause the computer to stop working. Therefore, the ransomware does not encrypt files located in the system directory of Windows, as well as files with the following extensions: ‘.sys, .dll, .lnk, .ini, .bat’. In addition, Maas virus does not encrypt files named ‘_readme.txt’. All other files will become the target of the malware, for example, the following file types can be encrypted:

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

All encrypted files become completely useless, their contents cannot be read in any way. To clearly show that the files are encrypted, the ransomware virus appends a new ‘.maas’ extension at the end of the filename of each encrypted file. This means the following: if the file had the name ‘photo-image.jpg’, then after it has been encrypted, it will be called ‘photo-image.jpg.maas’. In all directories where there are encrypted files, Maas virus drops a file named ‘_readme.txt’

Screenshot of the contents of ‘_readme.txt’ file (Maas ransom demand message)

This file contains text written by Maas authors. In this message, the criminals report that the user’s files were encrypted and the only way to get them back is to purchase a key and a decryptor. Attackers give the victim 72 hours. At this time, the key will cost $490, after 72 hours the ransom will increase to $980. The message also contains the contact information of the criminals, using which the victim can check the ability of the attackers to decrypt .maas files, as well as find out where to send the ransom.

Text presented in the _readme.txt file:

ATTENTION!

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:
https://we.tl/t-9fpnK9F5nP
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:
helpmanager@mail.ch

Reserve e-mail address to contact us:
restoremanager@airmail.cc

Your personal ID:

Threat Summary

In file ‘_readme.txt’, criminals scare victims by saying that encrypted files cannot be decrypted without paying a ransom. And unfortunately this is true, the contents of the files cannot be read while the files are encrypted, and a key and decryptor are needed to decrypt them.

Fortunately, there is a free Maas File Decrypt Tool. This decryptor can help each victim to decrypt .maas files for free. But in addition to the decryptor, the key is still necessary. As we reported above, the virus can use two types of keys. An offline key can be determined by researchers, but only criminals have an online key. Thus, files encrypted with so called ‘offline key’ can be decrypted. And all files that have been encrypted with so called ‘online key’ cannot yet be decrypted. In this case, the alternative methods listed below in this article can be used to recover the contents of these files.

How to remove Maas ransomware and Descrypt (restore) .maas files

If your documents, the files of your friends or colleagues, were encrypted by the Maas ransomware virus, then you need to follow the steps listed below that will help you to find and remove Maas, as well as decrypt or restore the encrypted files. It is very important to read the entire instruction manual carefully and make sure to understand it all. We advise you not to skip any steps, each of the steps is very important and must be completed by you. In order not to get confused and not miss an important point in the instructions, we recommend that you print this article or open it on your smartphone.

1. How to remove Maas ransomware virus
2. How to decrypt .maas files
3. How to restore .maas files
4. How to protect your PC from Maas ransomware

How to remove Maas ransomware virus

Before you start decrypting or recovering .maas files, you need to remove the Maas autostart entries. 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 Maas 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 Maas virus, then let us know in the comments, we will try to help you.

To remove Maas ransomware, follow the steps below:

1. Kill the Maas ransomware process
2. Disable the Maas ransomware Start-Up
3. Delete the Maas ransomware Task
4. Scan computer for malware

Kill the Maas ransomware process

Press CTRL, ALT, DEL keys together.

Click Task Manager. Select the “Processes” tab, look for something suspicious that is the Maas ransomware then right-click it and select “End Task” or “End Process” option.

A process is particularly suspicious: it is taking up a lot of memory (despite the fact that you closed all of your programs, its name is not familiar to you (if you are in doubt, you can always check the program by doing a search for its name in Google, Yahoo or Bing).

Disable the Maas ransomware 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 the Maas 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.

Scan computer for malware

Zemana Anti-Malware is a malware removal utility that performs a scan of the computer and displays if there are existing spyware, worms, adware software, ransomware virus, trojans and other malware residing on the system. If malicious software is detected, Zemana Anti Malware can automatically remove it for free. Zemana doesn’t conflict with other antimalware and antivirus applications installed on your PC system.

Installing the Zemana is simple. First you will need to download Zemana Anti Malware by clicking on the link below. Save it on your Desktop.

Zemana AntiMalware
164107 downloads
Author: Zemana Ltd
Category: Security tools
Update: July 16, 2019

When the download is finished, close all programs and windows on your PC. Double-click the install file called Zemana.AntiMalware.Setup. If the “User Account Control” prompt pops up as shown in the figure below, click the “Yes” button.

It will open the “Setup wizard” that will help you install Zemana Anti-Malware on your personal computer. Follow the prompts and do not make any changes to default settings.

Once install is complete successfully, Zemana Free will automatically start and you can see its main screen as shown on the image below.

Now click the “Scan” button to find the Maas crypto malware related folders,files and registry keys. While the Zemana Anti Malware utility is checking, you can see number of objects it has identified as being infected by malware.

When that process is finished, a list of all threats found is produced. You may remove items (move to Quarantine) by simply press “Next” button. Zemana Anti-Malware will begin to delete Maas ransomware virus and other security threats. Once disinfection is complete, you may be prompted to reboot the computer.

In order to be 100% sure that the computer no longer has the Maas ransomware virus, we recommend using Kaspersky virus removal tool (KVRT). This tool, 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 antivirus. This tool has great capabilities and therefore we recommend using KVRT in the last turn to be sure that the Maas ransomware has been removed.

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

Kaspersky virus removal tool
129082 downloads
Author: Kaspersky® lab
Category: Security tools
Update: March 5, 2018

Once the downloading process is complete, double-click on the KVRT icon. Once initialization procedure is done, you will see the KVRT screen as displayed 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 scan for the Maas crypto virus and other malicious software. A system scan can take anywhere from 5 to 30 minutes, depending on your machine. While the KVRT tool is checking, you can see count of objects it has identified as being affected by malicious software.

Once KVRT has completed scanning your PC system, it will open the Scan Results like below.

All detected threats will be marked. You can remove them all by simply press on Continue to start a cleaning task.

How to decrypt .maas files

Files with the extension ‘.maas’ are encrypted files. The virus uses a long key and a strong encryption algorithm, so it is impossible to decrypt files without a key and decryptor. Criminals demand a ransom for the key and the decryptor. Of course, even paying a ransom, there is no guarantee that victims will receive the required key and decryptor. Fortunately, there is a free Maas File Decrypt Tool that allows everyone to decrypt .maas files for free.

Maas File Decrypt tool (STOP Djvu decryptor)

To decrypt .maas files, use Maas File Decrypt tool:

• Go to the following link to download Maas File Decrypt tool.
  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.

Maas 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.

This video step-by-step guide will demonstrate How to remove Maas ransomware and Decrypt/Recover .maas files.

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 your files. This is very important, since the type of key determines whether it is possible to decrypt .maas files. We recommend using the second method, as it is more accurate.

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 – 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 Maas ransomware 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’, Maas 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.

Maas File Decrypt Tool : “No key for New Variant online ID”

If, when you try to decrypt .maas files, Maas 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 Maas 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.

Maas File Decrypt Tool : “No key for New Variant offline ID”

If, during decryption of .maas files, Maas 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 .maas files.

How to restore .maas files

If the Maas File Decrypt tool cannot decrypt the encrypted files or your data is encrypted with an online key, then there is no need to despair. Fortunately, there are several alternative methods that can allow everyone to recover the contents of encrypted files. Each of these methods does not involve the use of special knowledge and paid programs and can be performed by everyone. We have prepared an instruction with illustrations, which describes in detail the process of data recovery. Before you begin data recovery, if you have not completed step 1, then go back. You must be 100% sure that Maas ransomware virus is completely removed. We recommend using free malware removal tools.

Use ShadowExplorer to recover .maas files

The first and very simple way to restore encrypted files to the state in which they were before encryption is to restore files from their Shadow Copies. The Shadow Volume Copies are copies of files and folders that Windows automatically saved as part of system protection. This feature is fantastic at rescuing personal files that were locked by Maas ransomware. The guide below will give you all the details.

ShadowExplorer can be downloaded from the following link. Save it on your Windows desktop or in any other place.

ShadowExplorer
438809 downloads
Author: ShadowExplorer.com
Category: Security tools
Update: September 15, 2019

After the downloading process is finished, open a directory in which you saved it. Right click to ShadowExplorer-0.9-portable and select Extract all. Follow the prompts. Next please open the ShadowExplorerPortable folder as displayed in the following example.

Start the ShadowExplorer utility and then choose the disk (1) and the date (2) that you wish to recover the shadow copy of file(s) encrypted by the Maas crypto malware as shown below.

Now navigate to the file or folder that you wish to recover. When ready right-click on it and press ‘Export’ button as displayed below.

This video step-by-step guide will demonstrate How to recover encrypted files using Shadow Explorer.

Recover .maas files with PhotoRec

Another way to recover encrypted files is to use data recovery programs. There are many such programs, but most of them are paid. We recommend using a program called PhotoRec. It has all the necessary functions and is completely free.

Download PhotoRec on your PC by clicking on the following link.

PhotoRec
220669 downloads
Author: CGSecurity
Category: Security tools
Update: March 1, 2018

When 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 displayed on the image below.

Double click on qphotorec_win to run PhotoRec for Windows. It’ll show a screen as displayed in the figure below.

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

You will see a list of available partitions. Select a partition that holds encrypted personal files as displayed below.

Click File Formats button and choose file types to restore. You can to enable or disable the recovery of certain file types. When this is complete, press OK button.

Next, click Browse button to select where restored personal files should be written, then click Search. We strongly recommend that you use an external device to save the restored files!

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

When the recovery is complete, click on Quit button. Next, open the directory where recovered photos, documents and music are stored. You will see a contents as shown on the image below.

All recovered photos, documents and music are written in recup_dir.1, recup_dir.2 … sub-directories. If you’re searching 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 Maas ransomware

Most antivirus apps already have built-in protection system against the crypto virus. Therefore, if your machine 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 link below to download HitmanPro.Alert. Save it to your Desktop so that you can access the file easily.

HitmanPro.Alert
6829 downloads
Author: Sophos
Category: Security tools
Update: March 6, 2019

When the downloading process 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 shown a window where you can select a level of protection, as displayed in the figure below.

Now press the Install button to activate the protection.

Finish words

This article was created to help all victims of the Maas ransomware virus. We tried to give answers to the following questions: how to remove ransomware; how to decrypt .maas files; how to recover files, if the decryptor does not help; what is an online key and what is an offline key. We hope that the information presented in this article has helped you.

If you have questions, then write to us, leaving a comment below. If you need more help with Maas ransomware related issues, go to here.