An article created to show you how to remove the .MASTER file virus (BTCWare’s latest variant) and restore files that have been AES encrypted by this virus.
A ransomware infection, known to be the notorious BTCWare ransomware has been released as a new variant of the virus family. Unlike the other BTCWare versions, the .master iteration cannot be decrypted so far and uses an AES encryption algorithm to extort victims whose computers have been infected. The victims have to pay a hefty ransom fee in order to get their files decrypted by the ones behind the .master ransomware infection. In case your computer has been infected by this virus, we advise you to read this article thoroughly.
Threat Summary
Name | .master Ransomware |
Type | Ransomware, Cryptovirus |
Short Description | Encrypts the files on the infected computer using AES algorithm. Demands ransom payoff in BitCoin. The ransom varies. |
Symptoms | The files are encrypted with the .master file extension added to them. The virus drops a ransom note, named !#_RESTORE_FILES_#!.inf. |
Distribution Method | Spam Emails, Email Attachments, Executable files |
Detection Tool |
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Malware Removal Tool
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User Experience | Join Our Forum to Discuss .master Ransomware. |
Data Recovery Tool | Windows Data Recovery by Stellar Phoenix Notice! This product scans your drive sectors to recover lost files and it may not recover 100% of the encrypted files, but only few of them, depending on the situation and whether or not you have reformatted your drive. |
Update July 2017 A new version of BTCWare ransomware has come out into the wild. The virus uses a new malicious file extension, called .aleta which i adds to the encrypted files. Malware eresearchers believe it is spread via malicious spam e-mails carrying documents that contain malicious macros within them. Furthermore, researcher Michael Gillespie notified of a decrypter being released for the .MASTER BTCWare variant. You can now decrypt your files for free if you have saved them.
.master Ransomware Distribution Methods
Since the Master ransomware as many refer to it with this name is a variant of the BTCWareransomware, it may use the same methods to be spread and infect victims. The primary strategy of those methods is to send a massive spam campaign with e-mails that aim for one thing only – to convince unsuspecting users that the situation is critical and they must either click on an e-mail attachment or open a web link that may eventually lead to infection. To do this, Master ransomware may pretend to be a large organization, such as:
- Amazon
- PayPal
- FedEx
- DHL
- eBay
- Other
The messages usually have deceptive content, also known as “social engineering”. They may claim that there is an order awaiting confirmation or any other form invoices or important documents. Then, the user may be misled to click on the malicious e-mail.
BTCWare .master Ransomware – Analysis
After the infection file of the .master ransomware variant is opened, the virus begins to drop it’s payload. This happens by either extracting the payload onto the infected computer or simply connecting to a remote server hosted by the cyber-criminals and download it from there. After this has been done, the malicious files of Master ransomware are then dropped onto the computer of the user and may reside in the following locations:
- %AppData%
- %Roaming%
- %Local%
- %LocalLow%
- %Temp%
Those files include the ransom note of .master ransomware which is named !#RESTORE_FILES_#!.inf. It has the following content:
The .master ransomware virus may begin to modify multiple different Windows processes on the compromised computer system. This is done with the purpose of changing crucial settings on the infected computer, like deleting the backups and shadow volume copies by using the following Windows Command Prompt commands:
→ process call create “cmd.exe /c
vssadmin.exe delete shadows /all /quiet
bcdedit.exe /set {default} recoveryenabled no
bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures
.master Ransomware’s Encryption Process
For the encryption process of the BTCWare .master ransomware variant to succeed, the virus uses a patched AES encryption algorithm. If applied properly, it is very difficult to decrypt the encrypted files by this virus. The files that the .master ransomware looks for to encrypt on infected computers are usually the following:
→ .1c, .3fr, .accdb, .ai, .arw, .bac, .bay, .bmp, .cdr, .cer, .cfg, .config, .cr2, .crt, .crw, .css, .csv, .db, .dbf, .dcr, .der, .dng, .doc, .docm, .docx, .dwg, .dxf, .dxg, .eps, .erf, .gif, .htm, .html, .indd, .iso, .jpe, .jpeg, .jpg, .kdc, .lnk, .mdb, .mdf, .mef, .mk, .mp3, .mp4, .mrw, .nef, .nrw, .odb, .ode, .odm, .odp, .ods, .odt, .orf, .p12, .p7b, .p7c, .pdd, .pdf, .pef, .pem, .pfx, .php, .png, .ppt, .pptm, .pptx, .psd, .pst, .ptx, .r3d, .rar, .raw, .rtf, .rw2, .rwl, .sql, .sr2, .srf, .srw, .tif, .wb2, .wma, .wpd, .wps, .x3f, .xlk, .xls, .xlsb, .xlsm, .xlsx, .zip
After the .master ransomware has already encrypted the files, the virus then displays the files with the .master file extension after their name, for example:
It is believed that the cyber-criminals behind the .master virus have chosen this file extension in particular, because all of the previous variants of BTCWare have already been decrypted using a master decryption key which malware researchers uncovered earlier. And by doing this, the cyber-criminals might aim to mock those researchers.
Remove BTCWare and Restore .master Encrypted Files
Before removing BTCWare .master variant, it is important to backup the encrypted files beforehand.
Then, you can proceed with the removal of the virus. For it to succeed, we advise following the removal instructions underneath. They are specifically designed to help you in isolating the threat and removing all related objects to .master ransomware. In case you lack the experience to remove this virus manually, cybersec experts often advise to use and advanced anti-malware program which will automatically take care of the removal process for you.
In case you are looking for a method to restore your encrypted files, we urge you to do It by trying the alternative method for file recovery below. They are specifically designed to help you recover at least some of the encrypted files. You can find them in step “2. Restore files encrypted by .master Ransomware”.
Attention! SensorsTechForum strongly recommends that all malware victims should look for assistance only by reputable sources. Many guides out there claim to offer free recovery and decryption for files encrypted by ransomware viruses. Be advised that some of them may only be after your money.
As a site that has been dedicated to providing free removal instructions for ransomware and malware since 2014, SensorsTechForum’s recommendation is to only pay attention to trustworthy sources.
How to recognize trustworthy sources:
- Always check "About Us" web page.
- Profile of the content creator.
- Make sure that real people are behind the site and not fake names and profiles.
- Verify Facebook, LinkedIn and Twitter personal profiles.
- Guide 1: How to Remove .master Ransomware from Windows.
- Guide 2: Get rid of .master Ransomware from Mac OS X.
How to Remove .master Ransomware from Windows.
Step 1: Boot Your PC In Safe Mode to isolate and remove .master Ransomware





Step 2: Uninstall .master Ransomware and related software from Windows
Here is a method in few easy steps that should be able to uninstall most programs. No matter if you are using Windows 10, 8, 7, Vista or XP, those steps will get the job done. Dragging the program or its folder to the recycle bin can be a very bad decision. If you do that, bits and pieces of the program are left behind, and that can lead to unstable work of your PC, errors with the file type associations and other unpleasant activities. The proper way to get a program off your computer is to Uninstall it. To do that:



Step 3: Clean any registries, created by .master Ransomware on your computer.
The usually targeted registries of Windows machines are the following:
- HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
You can access them by opening the Windows registry editor and deleting any values, created by .master Ransomware there. This can happen by following the steps underneath:



Before starting "Step 4", please boot back into Normal mode, in case you are currently in Safe Mode.
This will enable you to install and use SpyHunter 5 successfully.
Step 4: Scan for .master Ransomware with SpyHunter Anti-Malware Tool
Step 5 (Optional): Try to Restore Files Encrypted by .master Ransomware.
Ransomware infections and .master Ransomware aim to encrypt your files using an encryption algorithm which may be very difficult to decrypt. This is why we have suggested a data recovery method that may help you go around direct decryption and try to restore your files. Bear in mind that this method may not be 100% effective but may also help you a little or a lot in different situations.
Simply click on the link and on the website menus on top, choose Data Recovery - Data Recovery Wizard for Windows or Mac (depending on your OS), and then download and run the tool.
Get rid of .master Ransomware from Mac OS X.
Step 1: Uninstall .master Ransomware and remove related files and objects
1. Hit the ⇧+⌘+U keys to open Utilities. Another way is to click on “Go” and then click “Utilities”, like the image below shows:
- Go to Finder.
- In the search bar type the name of the app that you want to remove.
- Above the search bar change the two drop down menus to “System Files” and “Are Included” so that you can see all of the files associated with the application you want to remove. Bear in mind that some of the files may not be related to the app so be very careful which files you delete.
- If all of the files are related, hold the ⌘+A buttons to select them and then drive them to “Trash”.
In case you cannot remove .master Ransomware via Step 1 above:
In case you cannot find the virus files and objects in your Applications or other places we have shown above, you can manually look for them in the Libraries of your Mac. But before doing this, please read the disclaimer below:
You can repeat the same procedure with the following other Library directories:
→ ~/Library/LaunchAgents
/Library/LaunchDaemons
Tip: ~ is there on purpose, because it leads to more LaunchAgents.
Step 3 (Optional): Try to Restore Files Encrypted by .master Ransomware.
Ransomware infections and .master Ransomware aim to encrypt your files using an encryption algorithm which may be very difficult to decrypt. This is why we have suggested a data recovery method that may help you go around direct decryption and try to restore your files. Bear in mind that this method may not be 100% effective but may also help you a little or a lot in different situations.
Simply click on the link and on the website menus on top, choose Data Recovery - Data Recovery Wizard for Windows or Mac (depending on your OS), and then download and run the tool.
.master Ransomware FAQ
What is .master Ransomware ransomware and how does it work?
.master Ransomware is a ransomware infection - the malicious software that enters your computer silently and blocks either access to the computer itself or encrypt your files.
Many ransomware viruses use sophisticated encryption algorithm how to make your files inaccessible. The goal of ransomware infections is to demand that you pay a ransom payment to get access to your files back.
How does .master Ransomware ransomware infect my computer?
Via several ways..master Ransomware Ransomware infects computers by being sent via phishing e-mails, containing virus attachment.
This attachment is usually masked as an important document, like an invoice, bank document or even a plane ticket and it looks very convincing to users.
After you download and execute this attachment, a drive-by download occurs and your computer is infected with the ransomware virus.
Another way, you may become a victim of .master Ransomware is if you download a fake installer, crack or patch from a low reputation website or if you click on a virus link. Many users report getting a ransomware infection by downloading torrents.
How to open ..master Ransomware files?
You can't. At this point the ..master Ransomware files are encrypted. You can only open them once they are decrypted.
Decryptor did not decrypt my data. What now?
Do not panic and backup the files. If a decryptor did not decrypt your ..master Ransomware files successfully, then do not despair, because this virus is still new.
One way to restore files, encrypted by .master Ransomware ransomware is to use a decryptor for it. But since it's a new virus, advised that the decryption keys for it may not be out yet and available to the public. We will update this article and keep you posted as soon as this decryptor is released.
How Do I restore "..master Ransomware" files (Other Methods)?
Yes, sometimes files can be restored. We have suggested several file recovery methods that could work if you want to restore ..master Ransomware files.
These methods are in no way 100% guarantee that you will be able to get your files back. But if you have a backup, your chances of success are much greater.
How do I get rid of .master Ransomware ransomware virus?
The safest way and the most efficient one for the removal of this ransomware infection is the use a professional anti malware software. It will scan for and locate .master Ransomware ransomware and then remove it without causing any additional harm to your important ..master Ransomware files.
Also, keep in mind that viruses like .master Ransomware ransomware also install Trojans and keyloggers that can steal your passwords and accounts. Scanning your computer with an anti-malware software will make sure that all of these virus components are removed and your computer is protected in the future.
What to Do If nothing works?
There is still a lot you can do. If none of the above methods seem to work for you, then try these methods:
- Try to find a safe computer from where you can can login on your own line accounts like One Drive, iDrive, Google Drive and so on.
- Try to contact your friends, relatives and other people so that they can check if they have some of your important photos or documents just in case you sent them.
- Also, check if some of the files that were encrypted it can be re-downloaded from the web.
- Another clever way to get back some of your files is to find another old computer, a flash drive or even a CD or a DVD where you may have saved your older documents. You might be surprised what will turn up.
- You can also go to your email account to check if you can send any attachments to other people. Usually what is sent the email is saved on your account and you can re-download it. But most importantly, make sure that this is done from a safe computer and make sure to remove the virus first.
More tips you can find on our forums, where you can also asks any questions about your ransomware problem.
How to Report Ransomware to Authorities?
In case your computer got infected with a ransomware infection, you can report it to the local Police departments. It can help authorities worldwide track and determine the perpetrators behind the virus that has infected your computer. Below, we have prepared a list with government websites, where you can file a report in case you are a victim of a cybercrime:
Cyber-security authorities, responsible for handling ransomware attack reports in different regions all over the world:
- Germany - Offizielles Portal der deutschen Polizei
- United States - IC3 Internet Crime Complaint Centre
- United Kingdom - Action Fraud Police
- France - Ministère de l'Intérieur
- Italy - Polizia Di Stato
- Spain - Policía Nacional
- Netherlands - Politie
- Poland - Policja
- Portugal - Polícia Judiciária
- Greece - Cyber Crime Unit (Hellenic Police)
- India - Mumbai Police - CyberCrime Investigation Cell
- Australia - Australian High Tech Crime Center
Reports may be responded to in different timeframes, depending on your local authorities.