Kiratos ransomware - How to remove

Kiratos is a serious virus that can affect Windows machines. It is ransomware of the DJVU type. If you are a victim of Kiratos, the infection can be devastating if you do not have a backup of your files and programs. It is important to remove Kiratos and find the way in which it infected your computer. The Kiratos virus is named after the file extension that it appends to the name of the encrypted files.

name.jpg -> name.jpg.kiratos

You know that your computer is infected with Kiratos when you find that your files have become unopenable that their names have been changed. Cryptography is used to restrict your access to your documents, pictures, films, songs, etc. Only the criminals in control of the Kiratos virus know the decryption key which can fix the files.

Kiratos also creates a text file with a message about how to contact the criminals and restore the files. The message is almost the same as here, but the email addresses are different: [email protected] and [email protected].

Why do cryptoviruses spread?

Kiratos cryptovirus is extortion and it’s how some criminals make money.

A lot of ransomware developers target small businesses. Sometimes they see themselves as providing a service, doing a favour for their victims. Like they are running an unsolicited bug bounty program, and their victims are the unwilling clients. These hackers believe that they deserve money for finding and displaying to people their security holes. Often the cost of restoring the files is at least a few thousand dollars. Some ransomware developers have a sense of honour and restore files after the payment, a lot of the criminals don’t bother and simply take the money.

However, small businesses are not the only ransomware targets. Individual people get their computers infected, too. Usually, they are asked for at least a few hundreds of dollars for the decryption key (Kiratos asks for $490).

The DJVU ransomware family, to which Kiratos belongs, has been at large for a few months now and they still develop and release new versions of their virus. Although this is completely illegal, a lot of victims don’t go to the police, or the police lack the resources to do anything about the cybercriminals. Kiratos is international, so the perpetrators are very difficult to track. Occasionally ransomware developers get arrested, but it’s rare.

How is ransomware distributed?

Infected email attachments is probably the most common way that ransomware spreads to individual PCs. Malicious spam mail uses social engineering techniques to trick people to open these infected files. Be careful about opening attachments, as the email address can look trustworthy even when the letter is not.

Another way to mass infect computers with ransomware is to hide them in files available for download through peer-to-peer services. Crack files for commercial software is a great disguise for Kiratos, especially since these files are often detected by antivirus applications even when they don’t contain a cryptovirus.

Remote Desktop Protocol is a way for ransomware distributors to infect machines individually.  Weak names and passwords are vulnerable, as well as the credentials that were used elsewhere if the data there was leaked. Leaked data is valuable because a lot of people reuse their names and even passwords in multiple accounts. This is why even a login name is useful information for a hacker. Criminals break into website and business databases, and the people whose data was exposed don’t always find out. So be safe and change your password regularly.

How to be safe against Kiratos?

If you use remote access software (like Remote Desktop), make sure that your password and name are complex and change your password regularly. Don’t keep the remote access software on when you don’t need it.

Create a files backup (Windows has tools to do this, take advantage of them) that you store separately from your computer — some cryptoviruses (including Kiratos) can erase the backup files that are on your computer.

The good news is that the DJVU family has a free decryptor developed for it, so it’s possible that Kiratos will have one, too, but it is very, very unlikely that all your files will ever be decrypted this way. Still, image the PC and save the image, or copy all the encrypted files and the ransom note, if you want to preserve them for the future in hopes that decryption will be available. Do this before you scan your machine with an antivirus.

How to get rid of the Kiratos cryptovirus

Scan your machine with an antivirus and remove the threats that are found. Use a good-quality program that you trust, for example, Spyhunter.

How to recover Kiratos ransomware encrypted files and remove the virus

Step 1. Restore system into last known good state using system restore

1. Reboot your computer to Safe Mode with Command Prompt:

for Windows 7 / Vista/ XP

• Start → Shutdown → Restart → OK.
• Press F8 key repeatedly until Advanced Boot Options window appears.
• Choose Safe Mode with Command Prompt.

for Windows 8 / 10

• Press Power at Windows login screen. Then press and hold Shift key and click Restart.
• Choose Troubleshoot → Advanced Options → Startup Settings and click Restart.
• When it loads, select Enable Safe Mode with Command Prompt from the list of Startup Settings.

 

2.Restore System files and settings.

• When Command Prompt mode loads, enter cd restore and press Enter.
• Then enter rstrui.exe and press Enter again.
• Click “Next” in the windows that appeared.
• Select one of the Restore Points that are available before Kiratos has infiltrated to your system and then click “Next”.
• To start System restore click “Yes”.

 

Step 2. Complete removal of Kiratos ransomware

After restoring your system, it is recommended to scan your computer with an anti-malware program, like Spyhunter and remove all malicious files related to Kiratos. You can check other tools here.  

Step 3. Restore Kiratos ransomware affected files using Shadow Volume Copies

If you do not use System Restore option on your operating system, there is a chance to use shadow copy snapshots. They store copies of your files that point of time when the system restore snapshot was created. Usually Kiratos tries to delete all possible Shadow Volume Copies, so this methods may not work on all computers. However, it may fail to do so. Shadow Volume Copies are only available with Windows XP Service Pack 2, Windows Vista, Windows 7, and Windows 8. There are two ways to retrieve your files via Shadow Volume Copy. You can do it using native Windows Previous Versions or via Shadow Explorer. a) Native Windows Previous Versions Right-click on an encrypted file and select Properties → Previous versions tab. Now you will see all available copies of that particular file and the time when it was stored in a Shadow Volume Copy. Choose the version of the file you want to retrieve and click Copy if you want to save it to some directory of your own, or Restore if you want to replace existing, encrypted file. If you want to see the content of file first, just click Open.

b) Shadow Explorer It is a program that can be found online for free. You can download either a full or a portable version of Shadow Explorer. Open the program. On the left top corner select the drive where the file you are looking for is a stored. You will see all folders on that drive. To retrieve a whole folder, right-click on it and select “Export”. Then choose where you want it to be stored.

Step 4. Use Data Recovery programs to recover Kiratos ransomware encrypted files

There are several data recovery programs that might recover encrypted files as well. This does not work in all cases but you can try this:

• We suggest using another PC and connect the infected hard drive as slave. It is still possible to do this on infected PC though.
• Download a data recovery program.
• Install and scan for recently deleted files.

Note: In many cases it is impossible to restore data files affected by modern ransomware. Thus I recommend using decent cloud backup software as precaution. We recommend checking out Carbonite, BackBlaze, CrashPlan or Mozy Home.