Restore Files Encrypted via RSA Encryption. Remove CryptoWall and Other Ransomware Manually - How to, Technology and PC Security Forum |

Restore Files Encrypted via RSA Encryption. Remove CryptoWall and Other Ransomware Manually

password-brute-force-stforumRansomware encryptions and infections have created havoc worth around 18 million USD. These type of attacks come from Trojan horses with preprogrammed scripts that encrypt the user files in mainly AES and RSA encryption algorithms. Ransomware infections have become a grave danger to inexperienced users who usually open email attachments without carefully thinking about their legitimacy. The threat itself can be removed with a particular anti-malware program, however, the encrypted files remain. This is a tutorial to help users in decrypting RSA encrypted data. The methods below were recommended by experts and were tried several times by users with a good result. However this is no guarantee that it will work for you.

What Is RSA Encryption Algorhytm?

RSA encryption algorithm is a type of language that, in this case, changes the normal code of the file with a unique key. This key can be decrypted via special software, but it requires a powerful machine since it is a time-costly process. RSA algorithm has been employed by the most traditional ransomware viruses that have caused massive devastations on a global scale – The CryptoWall Variants(2.0, 3.0), Bitcrypt and others. In this tutorial, we show you a possible method of decrypting your files and restoring them to their previous working state in case you have no backup on your operating system (OS). After the tutorial, we have provided instructions on how to enable Windows file history so your files can be backed up so you can protect yourself from future attacks. Make sure you take your time and do everything from the steps below and things should be fine for you.

Ransomware Removal Manual

Before doing this, make sure you backup your information on a USB stick or anything of this similarity. After that, make sure you download a reputable anti-malware software that will detect anything out of the ordinary and assist you with the removal of the threat. Download it to a safe PC and put it on yours and boot your computer in Windows online Safe Mode using the following manual:

1. Start Your PC in Safe Mode to Remove Ransomware

1. Start Your PC in Safe Mode to Remove Ransomware.

For Windows XP, Vista, 7 systems:

1. Remove all CDs and DVDs, and then Restart your PC from the “Start” menu.
2. Select one of the two options provided below:

For PCs with a single operating system: Press “F8” repeatedly after the first boot screen shows up during the restart of your computer. In case the Windows logo appears on the screen, you have to repeat the same task again.

For PCs with multiple operating systems: Тhe arrow keys will help you select the operating system you prefer to start in Safe Mode. Press “F8” just as described for a single operating system.

3. As the “Advanced Boot Options” screen appears, select the Safe Mode option you want using the arrow keys. As you make your selection, press “Enter“.
4. Log on to your computer using your administrator account

While your computer is in Safe Mode, the words “Safe Mode” will appear in all four corners of your screen.

For Windows 8, 8.1 and 10 systems:
Step 1: Open the Start Menu
Windows-10-0 (1)
Step 2: Whilst holding down Shift button, click on Power and then click on Restart.
Step 3: After reboot, the aftermentioned menu will appear. From there you should choose Troubleshoot.
Step 4: You will see the Troubleshoot menu. From this menu you can choose Advanced Options.
Windows-10-2 (1)
Step 5: After the Advanced Options menu appears, click on Startup Settings.
Windows-10-3 (1)
Step 6: Click on Restart.
Windows-10-5 (1)
Step 7: A menu will appear upon reboot. You should choose Safe Mode by pressing its corresponding number and the machine will restart.

2. Remove Ransomware automatically with SpyHunter Removal Tool.

2. Remove Ransomware automatically with Spy Hunter Malware – Removal Tool.

To clean your computer with the award-winning software Spy Hunter – donload_now_140
It is highly recommended to run a system scan before purchasing the full version of the software to make sure that the current version of the malware can be detected by SpyHunter.

Ransomware Files Restoration

For this particular tutorial, we have used .bitcrypt extension files, encrypted by ransomware, called Bitcrypt. We have also used Ubuntu version 14.04 which assisted us in using special software appropriate for this distribution. You can get it from their website’s download page and you can either:

-Install it along with your operating system by booting a live USB drive.

-Install it on a virtual drive (Recommended).

Here we have brief tutorials for both:

Installation of Ubuntu on your machine:

Step1: Get a USB flash drive that has above 2GB of space.

Step2: Download the free software, called Rufus from here and install it on your windows.

Step3: Configure Rufus by choosing NTFS as a system and selecting the USB drive as the one to be created as a bootable USB. After that boot the Linux image from the following button:


Make sure you locate it and select it from where you downloaded it.

Step4: After the flash drive is ready, restart your computer, and it should run the Ubuntu installation. If it does not, you should go to the BIOS menu by pressing the BIOS hotkey on startup for your PC (Usually it is F1) and from there select the first boot option to be the USB bootable drive or CD/DVD in case you have burnt Ubuntu on such.

Installation Of Ubuntu on your Virtual Drive

For this installation, you need to download VMware Workstation from their download page or any other Virtual Drive Management program. After installed you should:

Step1: Create a new virtual drive.

Step2: Set the drive size. Make sure you have a minimum of 20 gigabytes of free space fro Ubuntu on your computer. Also choose ‘Run as a single drive’.

Step 3: Select the ISO image. For this option, you should know where it is.

Step 4: After that play the Virtual Machine and it will install automatically.

File Decryption

Once you have Ubuntu or any other Linux distribution on your computer open the terminal by doing the following:


Then update your Linux and install greater version than Python 3.2 by typing the following in the terminal:

→sudo apt-get update
sudo apt-get install python3.2

Also, if your Linux does not have sqlite3 module, install it by typing:

→sudo apt-get install sqlite3 libsqlite3-dev
sudo gem install sqlite3-ruby

Now after we have Python installed, we need to download a script created by 2014 Airbus Defence and Space Cybersecurity. To do this click on this link. Download the file in your ‘Home’ folder after it prompts you where to save it. Keep this as in case it is not saved in this format.

Now that we have Python and the script, it is time to find out the key of the .bytrcypt encrypted file. To do this move your encrypted files ot the home folder by using the file manager:


After you located all of the encrypted files there along with the “” file type the following into the terminal to initiate the script:

→python ./ “Your_Encrypted_Document_Name_and_Format”

It will show an error, and this is entirely normal as long as you see this code:


This is the RSA code for this file. Now, we need to decrypt it, and we are halfway there. To do this download a program called cado-nfs2.0.tar.gz from their download page here. We recommend the 2.0 version. However, the newest version is also on a good level.

It will download a .tar archive file (.tar files are very similar to .rar or .zip files). Simply open it and click on the Extract button on top and choose the ‘Home’ folder. It should look like this:


After the we have all the files extracted in the ‘Home’ folder, we need to compile cado-nfs. To do this, open another terminal and type:

→cd cado-nfs-2.0

After this is set, it is time to run the key cracker. Important – this process can take from several hours to days to be finished. To begin the process type in your cd cado-nfs terminal:


After the process completes, you should see the following:

→Info:Complete Factorization: Total cpu/real-time for everything: hhhh/dddd
LongNumber1 LongNumber2

After we have the decrypted key, we need to insert in the “” script. Do this by opening in a text editor and finding this part of it:

→known_keys = { many long numbers }

We need to add before the second bracket (“}”) these lines:

The Previous Key, a column, opened parenthesis, LongNumber1, Comma, LongNumber2, closed parenthesis. It should look like this:

→The Previous Key:(LongNumber1,LongNumber2)

Be advised that you should do this only one time. After this it is time to decode the files. To do this type:

→python ./ “Your_Encrypted_Document.docx.bitcrypt”

Executing this command will make a file that is called “Your_Encrypted_Document.docx.bitcrypt.CLEAR”

Just rename the file by removing the .clear extension and you should be all set. Repeat the process for your other files as well. But remember that first you should find out their initial keys to decrypt them. You should be able to open them now. We hope this works for you.


The best defense against Ransomware threats is always the user himself. It is crucial to know which files you open and whether or not the locations of those files are safe or not. However if you are in an organization or somewhere where the computer is located in a public or work environment, it always opens it up to a direct attack that is even more dangerous. A real expert will say that the best computer is the one that is switched off, because it may have the best defenses, but the one who makes the errors is not the machine, it’s the man. This is why you should always keep enough knowledge and build up PC usage behavior that is security oriented.


Malware Removal Tool

Spy Hunter scanner will only detect the threat. If you want the threat to be automatically removed, you need to purchase the full version of the anti-malware tool.Find Out More About SpyHunter Anti-Malware Tool / How to Uninstall SpyHunter


Berta Bilbao

Berta is a dedicated malware researcher, dreaming for a more secure cyber space. Her fascination with IT security began a few years ago when a malware locked her out of her own computer.

More Posts


  1. Avatarlucas va

    Good afternoon,

    I get the error : “[-] Error parsing file footer” when I execute on my file encrypted …

    1. AvatarBertaB (Post author)

      Hello Lucas,

      This may be due to one of the following reasons:

      1) Old python version.

      sudo apt-get update python

      2) Error in file name or command.

      Check the command you typed carefully. Can you tell me which one is it? If it is this one:

      python ./ “MY ENCRYPTED FILE.jpg.bitcrypt”

      it should be typed with the brackets exactly as seen above.

      3)Error in the ‘’ file

      In case it doesnt work you shouldnt try to look for the issue since you may lose a lot of your time in doing so.
      Your best bet is to try DecrypterFixer. You can download it from here:

      It has a well made ‘’ file and should work for you.

      In case the first web link is broken, try this one:

      1. Avatarlucas va

        Hello, thanks you for your reply.
        My file is not in .bitcrypt extension because I was infected by CryptoWall 3.0

        I will try your solutions, thanks you.
        I will come to give you a feedback

        1. AvatarJohn John

          hello ,, you have some look on this,, you recover your files? can I try ,, thanks

  2. Avatarpatrick

    I have the same problem. My files are also infected by the Cryptowall 3.0. And the extension is ccc. Can I use this python script to decrypt ? Are there other possible solutions ?
    thx a lot

    1. AvatarBertaB (Post author)

      Hello Patrick,

      We are sorry to hear your files have been encrypted by ransomware. The .ccc extension may not belong to the CryptoWall threat. There are variants of other ransomware that pretend to be Cryptowall 3.0, possibly because it is the most vicious of them all so far. There is a tool that may help you, known as Tesla decryptor. More information in the link below.

      We have started a new topic in our security forum, with the intention to help as many users as possible. There it is:!/

      1. AvatarParawi

        Hi! All my files were encrypted by rsa4096, all has the extension .mp3. What should i do? Thks

  3. AvatarBrently

    I have a my VP’s computer at my desk right now that has the DecryptorMax ransomware. I have removed the trojan and malware in Safe Mode, but am looking for a way to decrypt the files. This has my VP’s first baby girl’s baby photos from the first couple months of her life, so these files are really important to her. They aren’t providing me the time to do the Linux decrypt, so looking for a tool. Hoping Kaspersky comes out with a tool to decrypt these. They have the crinf extension. Any help is appreciated.

    1. Milena DimitrovaMilena Dimitrova

      Hi Brently, we’re about to start a topic in our forum about DecryptorMax, and we’re also going to research it in depth. Can you please clarify what you meant by saying ‘They aren’t providing me the time to do the Linux decrypt’?


      the STF team

  4. AvatarGil


    I am getting the following error when running

    python3.4 ./ test.bitcrypt
    File “./”, line 99
    print “usage: %s ” % sys.argv[0]
    SyntaxError: Missing parentheses in call to ‘print’

    Any help would be great.

    Thank You,


    1. Milena DimitrovaMilena Dimitrova

      Hi Gil,

      What ransomware are you dealing with?

      Please join our forum and follow the topic about SyntaxError: Missing parentheses in call to ‘print’:'syntaxerror-missing-parentheses-in-call-to-print/

  5. AvatarGab

    so… just to double check if there’s no restore point and no shadow copy, there’s no way to get the files back from cryptowall 3.0 correct?

  6. Avataryohji

    do you have a method to decrypt files that is encrypted using cryptowall 4

    1. Milena DimitrovaMilena Dimitrova

      Hi yohji,

      Are you dealing with CryptoWall 4.0?

      1. AvatarGab

        Would you help me with cryptowall 3.0 please.

        1. Milena DimitrovaMilena Dimitrova

          Hi Gab,

          Can you please start a topic here:

          Thanks in advance :)

      2. AvatarKJ

        My files were infected by cryptowall 4.0 with ‘help_your_files’.
        I removed the cryptowall 4.0 using anti-malware softwares.
        Can I use the “” script to find out the key of the encrypted files by cryptowall 4.0?
        Would you tell me if you have other possible solutions for restoring the encrypted files?


      3. AvatarMehmet

        Ich habe auch das selber probleme mit cryptowall virüs aber weiss es nicht genau,welche version das ist.
        Es gibt in jeder ordner einen bild mit HELP_YOUR_FILES

        und folgende dateien formate ; .DZ7 .O1R .7FT .1Q .7429D .0PQGL .BR4 .7UV .2PF Usw…

        Können Sie mir bitte helfen?
        Ich habe sehr wichige fotos und text dokumenten.
        Mfg Mehmet

        1. AvatarFran

          Hola Mehmet, has conseguido arreglar los archivos? Mi virus tenia el mismo archivo que el tuyo.

        2. AvatarEffesse72

          Good morning, my problem is the same of your since 05/01/2016!

  7. AvatarVencislav Krustev

    Hello, KJ as far as we know so far most methods for decrypting files encrypted by cryptowall 4.0 have proven to be unsuccessful even by law enforcement. However what you can try is ask a question in the Cryptowall 4.0 topic in our forum and wait to see if you get any help from other affected users and experts in this subject. Here is the topic link, there are also some instructions included:

  8. AvatarMarc

    Has anyone been able to decrypt CryptoWall 3.0 encrypted files (2048 bit encryption) using this method?

  9. AvatarYannick

    Ayant été infecté par l’un de ces virus, je me demande lequel car il a encrypté un grand nombre de fichiers en rajoutant une extension vvv à chaque fois, rendant celui-ci invisible et en mettant dans chaque sous-répertoire plusieurs fichiers appelés “how_recover” ? Donc quel virus est-ce et quelle méthode pour retrouver ses fichiers crypés s’il y en a ?
    Merci beaucoup.


    1. Milena DimitrovaMilena Dimitrova

      Hello Yannick,

      Unfortunately, you have been attacked by TeslaCrypt. More information about the ransomware here:

  10. AvatarYannick


    Merci beaucoup. Oui, donc il n’y a rien à faire pour récupérer ses fichiers….

  11. AvatarCornel Goran

    Hi! I’ve also got some encrypted files that I’d like to decrypt. I have 2 files “5k5m3y.1mm” and “8co7o3co.ze4ha” and they look like this if I try to edit them with notepad:

    First thing first, how do I know what virus caused this?

    1. AvatarVencislav Krustev

      Hello @Corel Goran
      This is typical for Ransomware infections such as CTB Locker and CryptoWall 4.0. In order for me to be able to adequately provide you with assistance I would like you to send me a snip or a screenshot of any ransom message that you may see. It may be a .txt file on your desktop or a picture, named like this, for example:

      • Help_Decrypt_Your_Files
      • Help_Your_Files

      Attach the screenshots in your reply to this topic in our forum so that our experts may be able to relevantly assist you the best way they can:

      Forum Topic To Attach Your Screenshot

  12. AvatarCarsten

    Got the same problem since Thursday this week. Encrypted files have .micro extention. Kaspersky Rescue disc reported trojan-ransom.win32.bitman.fay to be the threat.
    Does the above described procedure work for .micro files as well?
    Many thanks for any help.

    1. AvatarCarsten

      I have found some files in My Documents folder named recover_file_***random_text***.txt that seem to contain keys. May these possibly be the keys to be retrieved by using phyton as described above?

  13. AvatarJoel

    As Carsten, I have same problem with “.micro” file.
    And as him, I have some file named “recover_file….txt”. Any idea about how to use them and if this solution works with .micro file?

  14. AvatarMauzinh0

    Same problem with *.micro file
    Same recover…txt
    Any news?
    Thank you

  15. Avatarnf

    Hello, I have also the problem with the *.micro extension.

  16. AvatarWilliam

    Mis archivos han quedado encintados con extension .locky, que virus me ataco? y que guía para recuperarlos me recomiendan


  17. Avatarstef

    Hello, j’ai bien les fichier HELP_FILE*.HTML et PNG
    Mes fichiers ont maintenant des noms et extensions aelatoires.
    Le nettoyage est fait sans probleme.
    Sur leur site où il faut payer, j’ai juste fait decryptage d’un fichier 512 ko max gratuitement, donc maintenant j’ai l’ancien fichier crypté 0sqn1xx.dh1w et le meme fichier decrypté : decrypted-file.jpg
    Ne serait-il pas possible d’apres ces 2 fichiers, d’en reconstruire la clef RSA ?? pour faire les tous les autres fichiers.
    Merci beaucoup, j’aime votre travail.

    1. AvatarBerta Bilbao (Post author)

      Hello, this appears to be CryptoWall 4.0. It has a very strong encryption, so without the key it’s going to be very hard to decrypt your files. The two files don’t hold a decryption key in themselves, but might help a decryptor program to see a similarity in its database and find a password.

      Try Rakhni Decryptor by Kaspersky – it’s a free tool and with the help of the two files it might find a key file on your computer if it’s not deleted. Also, take a look at the tips about CryptoWall 4.0 in our forum.

  18. AvatarVinny

    Hello, I did the commands and I received the page footer error… the file is encrypted with the “.locky” extension. is there something i could do?

  19. AvatarOswaldo Leonett

    I have the same problem. My files are also infected by redshitline(at) And the extension is xtbl- Can I use this python script to decrypt ? Are there other possible solutions ?


  20. AvatarMarco

    Hy Berta,
    I infected a month ago by cryptowall 4.0, the same of Oswaldo Leonett and I should know how to do… The instructions in this article are valid also for cryptowall 4? If I run .py script I can hope to decrypt my files of the script operate up to version 3.0 of cryptowall?
    Are There some new information about Cryptowall 4?

  21. AvatarMarco

    I correct myself, the contracted infection is the same of Stef with some HELP_FILE*.HTML and PNG.

  22. AvatarKarl Kristian dall

    Alle dine filer er blevet krypteret med RSA – 2048 og EAS -128 . INFORMATION om SA kan ses på da.Wikipedia. org/wiki/RSA. OG da.Wikipedia. org/wiki/Advanced Encryption Standard
    Dekryptering til hemmelig server på links
    Jeg tør ikke klikke på dem, måske der er mere virus. De vil nok have betaling for at dekryptere, og få adgang til mit Dankort.

    Kan der gøres noget.
    På forhånd tak
    Mvh. Karl

  23. AvatarKD Samir

    Le pirate a tous les fichiers et encrypte m’a demandé de rançon
    Je n’ai pas l’argent.
    Pouvez-vous aider?
    Si oui j’envoyer des fichiers (original – crypté) pour trouver le code.
    type de cryptage :
    public key RSA-2048 generated


Leave a Comment

Your email address will not be published. Required fields are marked *

Time limit is exhausted. Please reload CAPTCHA.

Share on Facebook Share
Share on Twitter Tweet
Share on Google Plus Share
Share on Linkedin Share
Share on Digg Share
Share on Reddit Share
Share on Stumbleupon Share