Kook ransomware is a malicious program designed to lock your files and keep them hostage until a ransom is paid
Kook ransomware – a version of the notorious cryptovirus that is known as Djvu. Since this is one of many versions in the prominent malware family, there are many features and functions that haven't changed much for the past year. Since August 2019, cybercrooks changed the encryption algorithm from AES to RSA, which made established decryption tools obsolete. This particular version of ransomware is appending files with .kook extension, so it can be distinguished from other variants, which also use the same ransom note – the text file named _readme.txt.
Unfortunately, the Kook ransomware virus is no different from other variants that came out in 2020, so there is little to no possibility to get your files recovered when the encryption algorithm is used to change the original code. The ransom note states about payment options and encourages people to contact criminals via helpmanager@mail.ch and restoremanager@airmail.cc emails. However, when you try to get more information about the payment, you may get tricked instead, and the sum of $490 or $980 might be lost forever.
In some cases, there is a tool that helps – Emsisoft Djvu decrypter. There is an issue of online vs offline IDs, so only some of the encoded files get decrypted this way. You can check your encrypted files with this tool and see if you deal with the older or newer variant of the STOP/Djvu virus. This fact determines the offline and online ID issue. You might have the option to decrypt files marked by .kook ransomware. However, the best option is to remove the threat completely and recover from your separate data backups.
| Name | Kook virus |
|---|---|
| Type | Ransomware[1] |
| Family | STOP virus/ Djvu ransomware |
| File extension | .kook – the file appendix that comes after a filetype extension and indicates encrypted files |
| Distribution | The threat uses methods involving malicious files. The virus can be spread via email attachments with malicious macros or from torrent platforms, pirating sites when malicious scripts get injected on software package files |
| Amount demanded from victims | $980 or $490, when the discount is offered |
| Ransom note | _readme.txt – a file that contains a direct message from criminals |
| Contact emails | helpmanager@mail.ch and restoremanager@airmail.cc |
| Elimination | To properly remove Kook ransomware from the system, you need a trustworthy anti-malware tool that |
| Repair | The system gets affected while alterations in system functions get made. Make sure to repair them or at least find affected parts with FortectIntego |
Kook ransomware can trigger changes in the system, so your device is not working as it supposed to. In most cases, cryptovirus affect data recovery options, file restoring features, security software, and other programs that could help with virus removal or file restoring functionalities.
Since the threat focuses on keeping malicious activities and files on the system, Kook ransomware triggers these changes immediately after the encryption. The behavior of the stealthy threat is not easily noticed because these changes happen in the background.
The victim of the .Kook files virus can notice the infection when files get marked using the .kook extension, and the ransom note is delivered on the screen, placed on the desktop, in other folders. The message in _readme.txt states:
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-gSEEREZ5tS
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:
helpmanager@mail.chReserve e-mail address to contact us:
restoremanager@firemail.ccYour personal ID:
This message should be ignored because there is no need to contact the criminals behind the Kook ransomware. Those people are not concerned about victims' files. The only purpose of this file virus is to get cryptocurrency from people directly by scaring them. Victims cannot know what to do when this text is displayed, and all the files get locked, so there are the ones who decide to pay. Unfortunately, it is not recommended by experts.[2]
Make sure to remove Kook ransomware properly from the system before you attempt any file restoring methods. Especially, when you rely on data backups from external devices that need to be plugged into the computer. You may lose all your data when the secondary encryption is launched.
Kook files virus is equipped with multiple features
The primary goal of ransomware, such as the Kook file virus, is to access your device, scan for susceptible files, lock them, and then demand ransom for their redemption. However, Djvu variants are a bit more sophisticated than that, as malicious actors seek to gain maximum benefits from each of the infections.
If you had no backups, Kook file recovery might not be possible – this fact is devastating by itself. However, it is important to note that malware also equipped with additional modules that could cause even more damage than permanent data loss. Here are a few examples and reasons why you should hurry to remove Kook ransomware from your system:
- Djvu ransomware variants are known to modify Windows “hosts” file in order to prevent victims from seeking help on security-focused websites, including 2-spyware.com. As a result, you might not be able to access these sites when seeking help. To revert this process, you should visit the following location and delete the “hosts” file:
C:\Windows\System32\drivers\etc\
- If you keep Kook ransomware running in the background, it might begin stealing information via your web browser. As a result, your banking details, various account information and other data can be stolen and sold for profits on the dark web;
This malware family is known to be collaborating with other strains, and people infected with Djvu were also found banking Trojan AZORult on their systems. In other words, it is possible that malicious actors might install other malware on your machine.
The different ways for Kook file recovery
Since Kook ransomware is the variant from a known virus family, it is known that previously developers used offline IDs, and the method allowed many victims to get their files back. Unfortunately, the technique is no longer used by these 2020 variants. Each victim gets a unique ID that is needed for the decryption process. It means that decryption tool development is even harder.
Even though the decryption is not possible, there are some options for the file recovery. Some variants that use offline IDs still can be decrypted, some types of data[3] also have solutions. Nevertheless, to get back to the system that works properly, you need a thorough system cleaning and Kook ransomware removal process that can eliminate the virus. For that purpose, you need anti-malware or security tools.
As for the data that is affected by .Kook file-encrypting virus, you need to rely on trustworthy data recovery options. A few listed below the guide. You can try to restore files from the cloud database or archive stored on the external device. Remember to repair system files also, so the machine can run as it supposed to. You can rely on FortectIntego for this purpose since the program can show affected files and corrupted functions for you.
Removing Kook virus cannot unlock your files
Your files will remain locked and encrypted even when you remove the virus using security tools or renewing the operating system entirely. Kook ransomware virus can alter various system settings, folders, and functions of the computer to remain persistent. The reversed encryption process is the best option, but there is no such decryption tool that could work at the moment.
You need to remove the Kook virus from the system, stop it from running, so it can no longer encrypt your files and then clear all the traces. This is how you completely terminate the threat. If you risk replacing encrypted files with safe copies while the virus is active, you can permanently lose files and money if you decide to pay up. Do not consider these options at all.
You need to pay attention to avoid the difficult Kook ransomware virus removal
As we mentioned Kook ransomware virus is distributed using various malicious files included on email attachments or packages with licensed software, game cheats, cracked program versions. These files get installed automatically and trigger the payload drop of the ransomware.
Kook virus removal gets affected by the processes and files planted in the background. Some security functions can get disabled, so you have fewer options for the elimination. However, tools like SpyHunterCombo Cleaner or MalwarebytesMalwarebytes are the best ones for such instances.
Unfortunately, these anti-malware or security tools cannot recover files encrypted by the virus or help to repair or remove Kook ransomware damage. You need a proper system application or a PC repair tool that can check and fix the damage on the system. Try FortectIntego for the virus damage repair. Then fully restore your device and all the affected files yourself.
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