Kook Virus ☣ (. Kook File Ransomware) — Decrypt+Removal Tool

What is “Kook”?

Ransomware is a specific kind of virus that encrypted your documents and then forces you to pay for them. DJVU (aka STOP) ransomware family was first revealed and discovered by virus analyst Michael Gillespie">².

Kook is basically similar to other representatives of ransomware like: Erif, Kuus, Bmic. Kook encrypted all common file types. Hence, users cannot use the own documents . Kook adds its own “.kook” extension into all files. For example, the file “video.avi”, will be changed into “video.avi.kook”. As soon as the encryption is accomplished, Kook drops a specific text file “_readme.txt” and puts it into all folders that contain the modified files.

This text asking payment is for get files back via decryption key:

The cryptography algorithm used by Kook is AES-256. So, if your files got encrypted with a specific decryption key, which is totally unique and there are no other copies. The sad reality is that it is impossible to recover the information without the unique key available.

In case if Kook worked in online mode, it is impossible for you to gain access to the AES-256 key. It is stored on a distant server owned by the frauds who promote the Kook ransomware.

For receiving decryption key the payment should be $980. To obtain the payment details, the victims are encouraged by the message to contact the frauds by email (), or via Telegram.

Do not pay for Kook!

_readme.txt file also indicates that the computer owners must get in touch with the Kook representatives during 72 hours starting from the moment of files where encrypted. On the condition of getting in touch within 72 hours, users will be granted a 50% rebate. Thus the ransom amount will be minimized down to $490). However, stay away from paying the ransom!

I strongly advise that you do not contact these frauds and do not pay. The one of the most real working solution to recover the lost data – just using the available backups, or use Decrypter tool.

The peculiarity of all such viruses apply a similar set of actions for generating the unique decryption key to recover the ciphered data.

Thus, unless the ransomware is still under the stage of development or possesses with some hard-to-track flaws, manually recovering the ciphered data is a thing you can’t perform. The only solution to prevent the loss of your valuable data is to regularly make backups of your crucial files.

Note that even if you do maintain such backups regularly, they ought to be put into a specific location without loitering, not being connected to your main workstation.

For instance, the backup may be kept on the USB flash drive or some alternative external hard drive storage. Optionally, you may refer to the help of online (cloud) information storage.

Needless to mention, when you maintain your backup data on your common device, it may be similarly ciphered as well as other data.

For this reason, locating the backup on your main PC is surely not a wise idea.