Kroput Ransomware

Also Known As: Kroput virus
Distribution: Low
Damage level: Severe

Kroput ransomware removal instructions

What is Kroput?

Discovered by Michael Gillespie, Kroput is a ransomware-type virus that belongs to the Djvu malware family. Kroput is designed to stealthily infiltrate computers and encrypt most stored files. During this procedure, Kroput adds the ".kroput" extension to the name of each encrypted file (e.g., "sample.jpg" is renamed to "sample.jpg.kroput"). Once data is encrypted, Kroput generates a text file ("_readme.txt") and places a copy in every existing folder. Other variants of this ransomware use the ".kroput1" and ".kropun" extensions for encrypted files.

The new text file contains a message stating that data is encrypted and can only be recovered using a unique decryption key. Unfortunately, this information is accurate. Kroput encrypts data using cryptography that generates a decryption key. Each victim receives a unique key and all are stored on a remote server controlled by cyber criminals. Therefore, users are forced to pay a ransom. The cost of the decryption key is $980, however, victims who contact these people within 72 hours will supposedly receive a 50% discount and the cost will drop to $490. Despite this, you should never agree to submit any payments. Cyber criminals are very likely to ignore victims, once payments are submitted. Therefore, they submit payments and receive nothing in return. Cyber criminals can never be trusted and, thus, all requests to submit payments or contact these people should be ignored. Unfortunately, there are no tools capable of cracking Kroput encryption and restoring data free of charge. The only solution is to restore everything from a backup.

Screenshot of a message encouraging users to pay a ransom to decrypt their compromised data:

Kroput decrypt instructions

Kroput is virtually identical to Promock, Yatron, ARTEMY, and dozens of other ransomware-type viruses. Note that although the developers are different, all of these infections have identical behavior - they encrypt data and make ransom demands. In most cases, size of ransom and type of encryption algorithm used are the only major differences. Most of these infections employ algorithms such as RSA, AES, and other similar algorithms that generate unique decryption keys. For this reason, it is virtually impossible to restore data without developers' involvement. The only possible solutions are the ransomware not being fully developed or having certain bugs/flaws (e.g., the key is hard-coded, stored locally, or similar). Ransomware is one of the main reasons why you should maintain regular data backups, however, store them on a remote server (e.g., Cloud) or unplugged storage device (Flash drive, external hard drive or similar). Locally stored backups are encrypted together with regular data.

How did ransomware infect my computer?

The method by which developers proliferate Kroput is currently unknown, however, in most cases, ransomware-type viruses are distributed using spam email campaigns, third party software download sources, fake software update tools, cracks, and trojans. Spam emails are used to proliferate malicious attachments that, once opened, download and install malware. Unofficial software download sources proliferate malicious executables by presenting them as legitimate software. This often tricks users into downloading and installing malware manually. Fake updaters infect computers by exploiting outdated software bugs/flaws or simply downloading and installing malware rather than updates. Cracking tools activate paid software free of charge, yet cyber criminals also use them to proliferate malware, and thus users can end up infecting their computers rather than gaining access to paid features. Finally, trojans are malicious applications which stealthily infiltrate computers and install additional malware.

Threat Summary:
NameKroput virus
Threat TypeRansomware, Crypto Virus, Files locker
SymptomsCan't open files stored on your computer, previously functional files now have a different extension, for example my.docx.locked. A ransom demanding message is displayed on your desktop. Cyber criminals are asking to pay a ransom (usually in bitcoins) to unlock your files.
Distribution methodsInfected email attachments (macros), torrent websites, malicious ads.
DamageAll files are encrypted and cannot be opened without paying a ransom. Additional password stealing trojans and malware infections can be installed together with a ransomware infection.

To eliminate Kroput virus our malware researchers recommend scanning your computer with Spyhunter.
▼ Download Spyhunter
Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

How to protect yourself from ransomware infections?

The main reasons for computer infections are poor knowledge and careless behavior. The key to safety is caution. Therefore, pay close attention when browsing the internet and downloading/installing/updating software. Think twice before open email attachments. If the receive file/link is irrelevant or the sender seems suspicious/unrecognizable, delete the email immediately and certainly do not open any attachments. Furthermore, download apps from official sources only, via direct download links. Third party download/installation tools should never be used, since most include rogue applications. Keep installed applications/operating system up-to-date, however, use only implemented functions or tools provided by the official developer. You should never use software cracking tools, since software piracy is considered a cyber crime and the risk of computer infections is extremely high. We strongly recommend that you have a reputable anti-virus/anti-spyware suite installed and running - these tools will help you to detect and remove viruses before they harm the system. If your computer is already infected with Kroput, we recommend running a scan with Spyhunter for Windows to automatically eliminate this ransomware.

Text presented in Kroput ransomware text file ("_readme.txt"):

Don't worry my friend, 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:
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" 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:

Screenshot of files encrypted by Kroput (".kroput" extension):

Files encrypted by Kroput

As with most ransomware from the Djvu family, Kroput displays a fake Windows update pop-up during encryption:

Djvu ransomware family fake update

IMPORTANT NOTE! - Ransomware-type infections from the Djvu malware family are designed to add a number of entries to the Windows hosts file. The entries contain URLs of various websites, most of which are related to malware removal. This is done to prevent users from accessing malware security websites and seeking help. Our website ( is also on the list. Removing these entries, however, is simple - you can find detailed instructions in this article (note that, although the steps are shown in the Windows 10 environment, the process is virtually identical on all versions of the Microsoft Windows operating system).

Screenshot of websites added to Windows hosts file:

Tro Ransomware adding websites to Windows Hosts file

Kroput ransomware removal:

Instant automatic removal of Kroput virus: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Spyhunter is a professional automatic malware removal tool that is recommended to get rid of Kroput virus. Download it by clicking the button below:
▼ DOWNLOAD Spyhunter By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

Quick menu:

Step 1

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in "Safe Mode with Networking":

Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in "Safe Mode with Networking":

Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button. In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.

windows 10 safe mode with networking

Video showing how to start Windows 10 in "Safe Mode with Networking":

Step 2

Log in to the account infected with the Kroput virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.

If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.

Video showing how to remove ransomware virus using "Safe Mode with Command Prompt" and "System Restore":

1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.

Boot your computer in Safe Mode with Command Prompt

2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.

system restore using command prompt type cd restore

3. Next, type this line: rstrui.exe and press ENTER.

system restore using command prompt rstrui.exe

4. In the opened window, click "Next".

restore system files and settings

5. Select one of the available Restore Points and click "Next" (this will restore your computer system to an earlier time and date, prior to the Kroput ransomware virus infiltrating your PC).

select a restore point

6. In the opened window, click "Yes".

run system restore

7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining Kroput ransomware files.

To restore individual files encrypted by this ransomware, try using Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of Kroput are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.

To restore a file, right-click over it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the "Restore" button.

Restoring files encrypted by CryptoDefense

If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode making its removal complicated. For this step, you require access to another computer.

To regain control of the files encrypted by Kroput, you can also try using a program called Shadow Explorer. More information on how to use this program is available here.

shadow explorer screenshot

To protect your computer from file encryption ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and EasySync CryptoMonitor, which artificially implant group policy objects into the registry to block rogue programs such as Kroput ransomware.

Note that Windows 10 Fall Creators Update includes a "Controlled Folder Access" feature that blocks ransomware attempts to encrypt your files. By default, this feature automatically protects files stored in the Documents, Pictures, Videos, Music, Favorites as well as Desktop folders.

Controll Folder Access

Windows 10 users should install this update to protect their data from ransomware attacks. Here is more information on how to get this update and add an additional protection layer from ransomware infections.

HitmanPro.Alert CryptoGuard - detects encryption of files and neutralises any attempts without need for user-intervention:

hitmanproalert ransomware prevention application

Malwarebytes Anti-Ransomware Beta uses advanced proactive technology that monitors ransomware activity and terminates it immediately - before reaching users' files:

malwarebytes anti-ransomware

  • The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups. More information on online backup solutions and data recovery software Here.

Other tools known to remove Kroput ransomware: