Kook Virus Removal Guide (+Decrypt .kook files)

Kook Virus Ransomware

Kook is a destructive software application functioning as typical ransomware. Michael Gillespie, the well-known virus researcher, very first discovered this new name in the DJVU ransomware family.

Kook was developed for the sole purpose to encrypt all popular file types. Rationally, as quickly as the file encryption is effectively accomplished, the users are unable to get access to them. Kook virus adds its own “.kook” to all the encrypted files. For example, the file “price_list.xls”, as soon as crypted by Kook, will be entitled as “price_list.xls.kook”. When the file encryption is achieved, Kook puts its own special text file (_readme.txt) into all the folders that save the encrypted files.

The message mentioned by document asking for the random os extremely similar to the notices offered by other ransomware dangers belonging to the DJVU family. The caution basically shows that the data has been encrypted and the only service to get access to it is to use a special standalone key. Regretfully, this declaration is absolutely true.

The approach to secure the files utilized by Kook is not entirely researched. Nevertheless, there is no doubt that each computer owner may be issued a special decryption key, which is definitely special. It is exceptionally hard to recuperate the information without the proper type in location.

“Don’t worry, you can return all your files!”, from _readme.txt message:

message from Kook virus

One more peculiarity of the Kook virus is that the users are unable to get access to the key. The decrypting key is hosted on an unique server under the complete control by the crooks who have actually introduced the Kook ransomware into the web. In order to acquire the key and bring back the crucial information, the users are told to get in touch with the frauds via e-mail or by telegram and to pay the ransom in the amount of $980.

The message also says that individuals need to contact the Kook authors within 72 hours upon the moment of the data file encryption. The alert shows that by doing so the people will get a 50% discount rate, for that reason, the ransom amount drops down to $490.

No matter what the quantity of the ransom is, we highly advise that you do not pay the ransom. There is no guarantee that these online crooks will keep their pledges, so they might not care at all what the victims feel about the file encryption, even when the quantity of the ransom is received into their accounts. Hence, paying ransom often does not lead to an effective healing. So, the users may simply lose their money for absolutely nothing.

Similarly, we urge you not to call the scams as they instruct. Do not move cash into their wallets. There are no applications that might split the Kook ransomware or bring back the data at no cost. For that reason, the only correct decision is to bring back the information from possible backups (if available).

Virus Summary

NameKook Ransomware
File Extensionkook
TypeRansomware
FamilyDJVU
Short DescriptionThe ransomware encrypts all the data stored on your system and requires a ransom to be paid on your part supposedly to recover your important files.
SymptomsFile encryption by the ransomware is performed by means of the AES-256 algorithm (CFB mode) encryption algorithm. Once the encryption is completed, the ransomware adds its special .kook extension to all the files modified by it.
Distribution MethodAdware bundles and software cracks
Similar InfectionsErif, Kuus, Bmic
Kook Removal Tool   GridinSoft Anti-Malware
Kook Decryption Tool   Emsisoft Djvu Decryptor

Do not forget that the Web is now filled with infections comparable to the Kook virus. For example, this specific danger is generally similar to Brusaf and other ransomware-type infections. These damaging energies have actually been established in order to encrypt the essential data and reveal the need for the users to pay the ransom. All these infections use the identical algorithm to create the particular key for successful data decryption.

Unless the Kook ransomware is still under the advancement process or has got some concealed bugs, it is not possible to restore the data by hand. Thus, the only working option to avoid the loss of your important information is to frequently keep current backups of all your essential documents.

Another crucial piece of suggestions is to store the backups on special storage not linked to your primary computer. For example, you may store it on the USB Flash Drive, or some external disk drive, or by using the cloud data storage services. Keeping the backups on your regular drive is very risky, given that the backup may likewise be secured by the Kook infection.

Leakages for the Kook ransomware attack.

Kook utilizes numerous courses to penetrate the vulnerable computer systems. It is not certain what specific approach was utilized in your case, however, the invasion might happen by means of the following channels:

  • bundling with third-party programs, mainly free apps;
  • spam emails from the unidentified senders;
  • sites providing complimentary hosting;
  • P2P (peer-to-peer) torrent downloads.

There are times when the Kook might camouflage itself as some genuine application, for example, through the deceptive alerts demanding setup of some software application update. This is the most typical trick utilized by the scams to inject the Kook infection files into the system. By doing this users partially participate in its installation, without clearly understanding the danger.

Furthermore, the scams might send out unsolicited spam email with challenging informs encouraging the people to open dubious attachments or click some download links, for instance, those encouraging individuals to open specific photos, text files, tax files and other information.

No doubt, opening these files or clicking on the malicious links may essentially harm the system. Fake Acrobat Reader upgrade notices may result in the Kook ransomware infiltration. Likewise, downloading the cracked software application might in addition consist of the ransomware installer. The last but not the least, installation of Kook may occur through some Trojan horses that may be set up stealthily into the system and without the user’s direct authorization or perhaps authorization.

Avoiding the Kook ransomware injection.

Obviously, there is no outright warranty that your computer system will be constantly devoid of any malware attacks, however, we would like to share some beneficial tips with you to make it much safer. Make sure to pay very very close attention while browsing the web and especially while getting cost-free programs. Do not open any suspicious e-mail accessories, especially if the sender is not known to you.

Do not forget that specific freeware installer may also consist of some other additional apps in the package. These additional applications may be really damaging. It is of utmost value to keep your anti-virus software and your operating system in general to be always correctly updated.

It is quite rational that downloading cracked apps is illegal, nevertheless, additionally, such unauthorized software application use may likewise bring severe damage to your system. For this reason, do not download any broken programs. Plus, the fact that your current anti-virus did not secure the system from the Kook ransomware is an excellent reason for you to reconsider your choices and change to another program that can render the safeguarding functions on a better level.

Below please find the quotation from the Kook text 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-2P5WrE5b9f
 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:
 restorealldata@firemail.cc
  
 Reserve e-mail address to contact us:
 gorentos@bitmessage.ch 

 Our Telegram account:
 @datarestore

Screenshot of files with “.kook” extension added by the ransomware:”

Kook Ransomware - encrypt files with .kook extension

Use GridinSoft Anti-Malware to remove Kook ransomware from your computer

1.Download GridinSoft Anti-Malware.

You can get GridinSoft Anti-Malware by clicking the button below:

  GridinSoft Anti-Malware

2. Double-click on the setup file.

When setup file has finished downloading, double-click on the setup-antimalware-ag.exe file to install GridinSoft Anti-Malware on your computer.
GridinSoft Anti-Malware
An User Account Control asking you about to allow GridinSoft Anti-Malware to make changes to your device. So, you should click “Yes” to continue with the installation.
GridinSoft Anti-Malware Setup

3. Press Install button for run GridinSoft Anti-Malware.

GridinSoft Anti-Malware Install

3.Once installed, GridinSoft Anti-Malware will automatically run.

GridinSoft Anti-Malware  Start

4. Wait for the GridinSoft Anti-Malware scan to complete.

GridinSoft Anti-Malware will automatically start scanning your computer for Win Speedup 2018 and other malicious programs. This process can take a 20-30 minutes, so we suggest you periodically check on the status of the scan process.
GridinSoft Anti-Malware Scan

5. Click on “Clean Now”.

When the scan has completed, you will see the list of infections that GridinSoft Anti-Malware has detected. To remove them click on the “Clean Now” button in right corner.
GridinSoft Anti-Malware Scan Result

Use Emsisoft Decryptor for restore kook files

You can download Emsisoft Decryptor by clicking the button below:

  Emsisoft Decryptor

  1. Run the decryptor as an administrator. The license terms will show up, which you have to agree to by clicking the “Yes” button.
  2. Once the license terms are accepted, the primary decryptor user interface opens.
  3. By default, the decryptor will pre-populate the locations to decrypt with the currently connected drives and network drives. Additional locations can be added using the Add” button.
  4. Decryptors typically offer various options depending on the particular malware family. The available options are located in the Options tab and can be enabled or disabled there. You can find a detailed list of the available Options below.
  5. After you have added all the locations you want to decrypt to the list, click the “Decrypt” button to start the decryption process. The screen will switch to a status view, informing you about the current process and decryption status of your files
  6. The decryptor will inform you once the decryption process is finished. If you require the report for your personal records, you can save it by clicking the “Save log” button. You can also copy it straight to your clipboard to paste it into emails or forum posts if you are asked to.
Sending
User Review
5 (1 vote)
Comments Rating 0 (0 reviews)

About Daniel Zimmermann

Daniel Zimmermann has been writing on security and malware subjects for many years and has been working in the security industry for over 10 years. Daniel was educated at the Saarland University in Saarbrücken, Germany and currently lives in New York.

Check Also

How to get rid of Mol16.biz advertisements

The Mol16.biz pop-ups are a social engineering attack that attempts to trick users into signing …

One comment

  1. it doesn’t work it seams there is a new ID for kook virus doesn’t exist in this program

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.