Kuub Virus Removal Guide (+Decrypt .kuub files)

Kuub – General Info

Kuub is a malicious software working as common ransomware. Michael Gillespie, the widely known virus researcher, first found this new name in the DJVU ransomware family.

Kuub was created for the sole function to encrypt all popular file types. Rationally, as quickly as the encryption is effectively achieved, the users are unable to get access to them. Kuub virus includes its own “.kuub” to all the encrypted files. For instance, the file “price_list.xls”, once crypted by Kuub, will be titled as “price_list.xls.kuub”. When the file encryption is achieved, Kuub puts its own special text file (_readme.txt) into all the folders that store the encrypted files.

The message stated by _readme.txt requesting for the random os really similar to the notices offered by other ransomware risks coming from the DJVU family. The warning basically indicates that the information has been encrypted and the only service to get access to it is to use a special standalone key. Regretfully, this declaration is absolutely real.

The technique to secure the files utilized by Kuub is not entirely looked into. However, there is no doubt that each computer owner may be provided an unique decryption key, which is absolutely unique. It is extremely difficult to recover the information without the suitable key in location.

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

message from Kuub virus

One more peculiarity of the Kuub virus is that the users are not able to get access to the key. The decrypting key is hosted on a special server under the complete control by the criminals who have introduced the Kuub infection into the internet. In order to acquire the key and bring back the essential data, the users are told to connect with the frauds via email or by telegram and to pay the ransom in the amount of $980.

The message also states that individuals must call the Kuub authors within 72 hours upon the minute of the data encryption. The alert suggests that by doing so individuals 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 recommend that you do not pay the ransom. There is no guarantee that these online criminals will keep their promises, so they may not care at all what the victims feel about the encryption, even when the amount of the ransom is received into their accounts. Thus, paying ransom typically does not lead to a successful recovery. So, the users might just lose their money for nothing.

Similarly, we advise you not to contact the frauds as they instruct. Do not move loan into their wallets. There are no applications that might break the Kuub virus or restore the information at no charge. Therefore, the only correct choice is to restore the information from possible backups (if offered).

Virus Summary

NameKuub Ransomware
File Extensionkuub
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-556 algorithm (CFB mode) encryption algorithm. Once the encryption is completed, the ransomware adds its special .kuub extension to all the files modified by it.
Distribution MethodAdware bundles and software cracks
Similar InfectionsBoot, Nesa, Karl
Removal Tool   GridinSoft Anti-Malware

Do not forget that the Web is now filled with infections similar to the Kuub virus. For instance, this particular risk is basically identical to Brusaf and other ransomware-type infections. These harmful energies have been developed in order to secure the important data and reveal the demand for the users to pay the ransom. All these infections use the similar algorithm to create the specific key for effective data decryption.

Unless the Kuub ransomware is still under the advancement process or has got some concealed bugs, it is not possible to restore the information manually. Hence, the only working service to prevent the loss of your essential data is to regularly maintain up-to-date backups of all your essential documents.

Another essential piece of advice is to save the backups on unique storage not linked to your main PC. For instance, you might store it on the USB Flash Drive, or some external hard disk drive, or by using the cloud data storage services. Keeping the backups on your routine drive is really dangerous, since the backup might likewise be secured by the Kuub ransomware.

Leakages for the Kuub ransomware attack.

Kuub utilizes many courses to penetrate the susceptible computers. It is not particular what specific approach was used in your case, however, the invasion might occur through the following channels:

  • bundling with third-party programs, generally freeware;
  • spam emails from the unknown senders;
  • sites supplying free hosting;
  • P2P (peer-to-peer) torrent software.

There are times when the Kuub ransomware might disguise itself as some authentic application, for instance, through the misleading informs demanding installation of some software application update. This is the most common technique utilized by the frauds to inject the Kuub infection files into the system. In this manner users partially participate in its setup, without clearly comprehending the danger.

Moreover, the frauds might send out unsolicited spam email with challenging signals encouraging individuals to open dubious attachments or click some download links, for example, those motivating the people to open certain photos, text files, tax documents and other information.

No doubt, opening these files or clicking on the malicious links might basically harm the system. Fake Media Player upgrade alerts may cause the Kuub ransomware seepage. Similarly, downloading the split software application might furthermore include the ransomware installer. The last but not the least, installation of Kuub might take place through some Trojan horses that may be set up stealthily into the system and without the user’s direct consent and even permission.

Preventing the Kuub ransom virus attack.

Obviously, there is no absolute assurance that your computer system will be always free of any malware attacks, nevertheless, we want to share some useful tips with you to make it much safer. Ensure to pay really close attention while searching the web and especially while downloading cost-free programs. Do not open any dubious e-mail attachments, particularly if the sender is not understood to you.

Do not forget that certain freeware installer might also consist of some other extra apps in the package. These extra applications may be really damaging. It is of utmost value to keep your anti-virus software and your os in basic to be always effectively updated.

It is rather logical that downloading cracked apps is unlawful, nevertheless, additionally, such unauthorized software application use may also bring major damage to your computer. Thus, do not download any cracked programs. Plus, the reality that your existing anti-virus did not protect the system from the Kuub ransomware is an excellent factor for you to reassess your choices and change to another program that can render the protecting functions on a far better level.

Below please find the quotation from the Kuub text file:

 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:
 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:
 Reserve e-mail address to contact us:
 Our Telegram account:

Screenshot of files with “.kuub” extension added by the virus:”

Kuub Ransomware - encrypt files with .kuub extension

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

1.Download GridinSoft Anti-Malware.

You can download 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

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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.

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