Djvu VirusRansomwareRemoval Guide

Qstx Virus Removal Guide (+Decrypt .qstx files)

Qstx Virus Ransomware

Qstx is a malicious software application working as typical ransomware. Michael Gillespie, the well-known virus researcher, first found this new name in the DJVU ransomware family.

Qstx was developed for the sole function to encrypt all popular file types. Rationally, as quickly as the file encryption is successfully achieved, the users are not able to get access to them. Qstx virus adds its own “.qstx” to all the encrypted data. For example, the file “price_list.xls”, as soon as modified by Qstx, will be entitled as “price_list.xls.qstx”. As soon as the file encryption is achieved, Qstx puts its own distinct text document (_readme.txt) into all the folders that store the encrypted files.

The alert specified by text file requesting the random os really similar to the alerts given by other ransomware risks coming from the DJVU family. The warning generally shows that the files have been secured and the only solution to get access to it is to use a special standalone key. Regretfully, this statement is absolutely true.

The approach to encrypt the files utilized by Qstx is not totally investigated. Nevertheless, there is no doubt that each computer owner may be issued an unique decryption key, which is definitely special. It is exceptionally tough to recover the information without the suitable key in place.

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

message from Qstx virus

One more peculiarity of the Qstx virus is that the users are not able to get access to the key. The decrypting key is hosted on an unique server under the complete control by the criminals who have released the Qstx infection into the world wide web. In order to acquire the key and bring back the essential information, the users are told to connect with the scams through email or by telegram and to pay the ransom in the quantity of $980.

The message also says that individuals must contact the Qstx authors within 72 hours upon the moment of the information encryption. The alert shows that by doing so individuals will get a 50% discount, therefore, the ransom amount drops down to $490.

No matter what the amount of the ransom is, we highly recommend that you do not pay the ransom. There is no warranty that these online crooks will keep their guarantees, so they may 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 a successful healing. So, the users might simply lose their money for nothing.

Similarly, we prompt you not to call the scams as they instruct. Do not move cash into their wallets. There are no applications that might split the Qstx ransomware or restore the information for free. Therefore, the only appropriate decision is to restore the information from possible backups (if readily available).

Virus Summary

NameQstx Ransomware
File Extensionqstx
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 .qstx extension to all the files modified by it.
Distribution MethodAdware bundles and software cracks
Similar InfectionsLokas, Besub, Nusar
Qstx Removal Tool   GridinSoft Anti-Malware
Qstx Decryption Tool   Emsisoft Djvu Decryptor

Do not forget that the Internet is now loaded with infections comparable to the Qstx ransomware. For instance, this particular danger is basically identical to Brusaf and other ransomware-type infections. These destructive utilities have been developed in order to secure the crucial information and reveal the need for the users to pay the ransom. All these infections use the identical algorithm to produce the specific key for effective information decryption.

Unless the Qstx ransomware is still under the development process or has actually got some concealed bugs, it is not possible to bring back the information manually. Therefore, the only working solution to prevent the loss of your important data is to regularly maintain up-to-date backups of all your crucial data.

Another important piece of suggestions is to save the backups on special storage not linked to your primary computer. For instance, you might save it on the USB Flash Drive, or some external drive, or by using the cloud data storage services. Keeping the backups on your system drive is extremely dangerous, considering that the backup may likewise be encrypted by the Qstx infection.

Leakages for the Qstx ransomware attack.

Qstx uses many courses to penetrate the vulnerable computer systems. It is not specific what specific technique was utilized in your case, however, the intrusion may occur through the following channels:

  • bundling with third-party programs, primarily free software;
  • spam emails from the unidentified senders;
  • websites offering free hosting;
  • P2P (peer-to-peer) torrent downloads.

There are times when the Qstx may camouflage itself as some authentic application, for instance, through the misleading notifies demanding installation of some software application update. This is the most typical trick used by the scams to inject the Qstx virus files into the system. This way users partly take part in its installation, without clearly understanding the danger.

Moreover, the scams may send out unsolicited spam email with challenging informs encouraging the people to open dubious attachments or click some download links, for instance, those motivating individuals to open certain pictures, text files, tax documents and other info.

No doubt, opening these files or clicking on the destructive links might essentially harm the system. Fake Acrobat Reader upgrade notices may lead to the Qstx ransomware seepage. Likewise, downloading the cracked software may in addition consist of the ransomware installer. The last however not the least, setup of Qstx may occur through some Trojan horses that might be set up stealthily into the system and without the user’s direct consent or perhaps consent.

Preventing the Qstx attack.

Obviously, there is no absolute assurance that your computer system will be always devoid of any malware attacks, nevertheless, we wish to share some beneficial suggestions with you to make it much safer. Make certain to pay very close attention while searching the web and specifically while downloading cost-free programs. Do not open any suspicious email accessories, especially if the sender is not known to you.

Do not forget that particular freeware installer might also consist of some other additional apps in the bundle. These extra applications might be very damaging. It is of utmost value to keep your anti-virus software application and your os in general to be constantly effectively updated.

It is rather logical that downloading cracked programs is unlawful, nevertheless, additionally, such unapproved apps use might also bring serious damage to your system. Hence, do not download any broken programs. Plus, the fact that your existing anti-virus did not safeguard the system from the Qstx ransomware is a good factor for you to reconsider your choices and change to another program that can render the protecting functions on a much better level.

Below please find the quotation from the Qstx 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 “.qstx” extension added by the ransomware:”

Qstx Ransomware - encrypt files with .qstx extension

Use GridinSoft Anti-Malware to remove Qstx 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

Use Emsisoft Decryptor for restore qstx 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.
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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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