Removal of the Dqb ransomware-type virus

Also Known As: Dqb virus
Distribution: Low
Damage level: Severe

Dqb ransomware removal instructions

What is Dqb?

Dqb is yet another ransomware infection discovered by Jakub Kroustek. It is quite advanced and belongs to the Dharma malware family. After successful infiltration, Dqb encrypts most stored data using RSA-1024 cryptography and renames each file by appending the victim's unique ID, developer's email address, and ".dqb" extension. For example, "1.jpg" might be renamed to a filename such as "[].dqb". After successful encryption, Dqb generates a text file ("RETURN FILES.txt", which is placed on the desktop) and opens a pop-up window.

The text file contains a message claiming that data is encrypted and that victims must contact cyber criminals to restore it. The pop-up window, however, provides much more detail. It states that data is encrypted using RSA-1024 cryptography and that victims must purchase a decryption tool/key to restore it. Therefore, only the cyber criminals can decrypt compromised files. Unfortunately, this information is accurate. RSA-1024 is an asymmetric encryption algorithm that generates two unique keys (public [encryption] and private [decryption]) for each victim. Restoring data without the private key is impossible. Criminals hide all keys on a remote server and blackmail victims by offering paid recovery of their files. The size of ransom is not specified. All details are provided via email, however, criminals usually demand $500-$1500 in a form of cryptocurrency. The message also states that victims are permitted to attach a single file (up to 1 MB, non-archived), which is restored and returned as a 'guarantee' that these people are capable of decrypting files and can be trusted. In fact, ransomware developers often ignore victims after payments are submitted. Therefore, paying usually gives no positive result and users are scammed. Unfortunately, Dqb is undecryptable ransomware - there are no tools capable of cracking the RSA algorithm and restoring data free of charge. The only solution is to restore everything from a backup, if one has been created.

Screenshot of a message encouraging users to pay a ransom to decrypt their compromised data:

Dqb decrypt instructions

The internet is full of ransomware infections that share many similarities. The list of examples includes (but is not limited to) Lokas, Boooam, Isolated, and CAGO. Although the developers differ, all of these infections have virtually identical behavior - they encrypt data and make ransom demands. Type of cryptography and size of ransom are the only major differences. Unfortunately, these encryptions often perform cryptographies such as RSA, AES, and similar, that generate unique decryption keys. Therefore, restoring files without developers' involvement is virtually impossible. The only possible scenarios are the ransomware not being fully developed and/or having certain bugs/flaws (e.g., the key is hard-coded, stored locally, or similar). Ransomware presents a strong case for maintaining regular backups, however, backups can be compromised together with regular data. Therefore, store them on a remote server or unplugged storage device. There is always the chance that storage devices/servers can be damaged. Therefore, we strongly advise you to have multiple backup copies stored in different locations.

How did ransomware infect my computer?

Ransomware infections are typically proliferated using the following tools/methods: trojans, fake software updaters and 'cracking' tools, third party software download sources, and spam email campaigns. Trojans are malicious applications designed to cause "chain infections". They infiltrate computers and download/install additional malware. Fake updaters are usually promoted in two ways: by exploiting bugs/flaws of outdated software or simply downloading and installing malware rather than updates. Cracking tools bypass paid software activation, however, most are fake and simply inject malware into the system rather than providing access to paid features. Cyber criminals also use various unofficial download sources (e.g., freeware download websites, free file hosting sites, Peer-to-Peer [P2P] networks, etc.) to proliferate malware by presenting it as legitimate software. In this way, users are tricked into downloading and installing malware rather than updates. Finally, spam campaigns are employed to send hundreds of thousands of deceptive emails containing malicious attachments and messages encouraging recipients to open them. These attachments are often presented as 'important documents' such as receipts, invoices, bills or similar. These are attempts to give the impression of legitimacy and increase the chance of tricking recipients.

Threat Summary:
Name Dqb virus
Threat Type Ransomware, Crypto Virus, Files locker
Encrypted Files Extension .dqb (this ransomware also appends filenames with the victim's unique ID and developer's email address).
Ransom Demanding Message Pop-up window, RETURN FILES.txt text files.
Cyber Criminal Contact,
Detection Names Avast (Win32:RansomX-gen [Ransom]), BitDefender (Trojan.Ransom.Crysis.E), ESET-NOD32 (A Variant Of Win32/Filecoder.Crysis.P), Kaspersky (, Full List Of Detections (VirusTotal)
Symptoms Cannot open files stored on your computer, previously functional files now have a different extension (for example, my.docx.locked). A ransom demand message is displayed on your desktop. Cyber criminals demand payment of a ransom (usually in bitcoins) to unlock your files.
Distribution methods Infected email attachments (macros), torrent websites, malicious ads.
Damage All files are encrypted and cannot be opened without paying a ransom. Additional password-stealing trojans and malware infections can be installed together with a ransomware infection.

To eliminate Dqb virus our malware researchers recommend scanning your computer with Spyhunter.
▼ Download Spyhunter
Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

How to protect yourself from ransomware infections?

The main reasons for computer infections are poor knowledge of these threats and careless behavior. The key to safety is caution. Therefore, pay close attention when browsing the Internet and downloading, installing, and updating software. All received email attachments should be handled with cares. Links/files that are irrelevant or those received from suspicious/unrecognizable addresses should never be opened. Download programs from official sources only, preferably using direct download links. Be aware that third party downloaders/installers often include rogue applications, and thus such tools should never be used. Keep installed applications and operating systems up-to-date, however, use implemented functions or tools provided by the official developer. Bear in mind that software piracy is a cyber crime and most cracking tools are fake. Therefore, never attempt to crack installed programs. Have a reputable anti-virus/anti-spyware suite installed and running, since this will detect and eliminate computer infections before they can harm the system. If your computer is already infected with Dqb, we recommend running a scan with Spyhunter for Windows to automatically eliminate this ransomware.

Text presented in Dqb ransomware pop-up window:

You can send us up to 1 file for free decryption. The total size of files must be less than 1Mb (non archived), and files should not contain valuable information. (databases,backups, large excel sheets, etc.)
When you make sure of decryption possibility transfer the money to our bitcoin wallet. As soon as we receive the money we will send you:
1. Decryption program.
2. Detailed instruction for decryption.
3. And individual keys for decrypting your files.
Do not rename encrypted files.
Do not try to decrypt your data using third party software, it may cause permanent data loss.
Decryption of your files with the help of third parties may cause increased price (they add their fee to our) or you can become a victim of a scam.

Screenshot of Dqb text file ("RETURN FILES.txt"):

Dqb text file

Text presented within this file:

All your data is encrypted!
for return write to mail: or

Screenshot of files encrypted by Dqb (".dqb" extension):

Files encrypted by Dqb

Dqb ransomware removal:

Instant automatic removal of Dqb virus: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Spyhunter is a professional automatic malware removal tool that is recommended to get rid of Dqb virus. Download it by clicking the button below:
▼ DOWNLOAD Spyhunter By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

Quick menu:

Step 1

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in "Safe Mode with Networking":

Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in "Safe Mode with Networking":

Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button. In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.

windows 10 safe mode with networking

Video showing how to start Windows 10 in "Safe Mode with Networking":

Step 2

Log in to the account infected with the Dqb virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.

If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.

Video showing how to remove ransomware virus using "Safe Mode with Command Prompt" and "System Restore":

1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.

Boot your computer in Safe Mode with Command Prompt

2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.

system restore using command prompt type cd restore

3. Next, type this line: rstrui.exe and press ENTER.

system restore using command prompt rstrui.exe

4. In the opened window, click "Next".

restore system files and settings

5. Select one of the available Restore Points and click "Next" (this will restore your computer system to an earlier time and date, prior to the Dqb ransomware virus infiltrating your PC).

select a restore point

6. In the opened window, click "Yes".

run system restore

7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining Dqb ransomware files.

To restore individual files encrypted by this ransomware, try using Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of Dqb are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.

To restore a file, right-click over it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the "Restore" button.

Restoring files encrypted by CryptoDefense

If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode making its removal complicated. For this step, you require access to another computer.

To regain control of the files encrypted by Dqb, you can also try using a program called Shadow Explorer. More information on how to use this program is available here.

shadow explorer screenshot

To protect your computer from file encryption ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and EasySync CryptoMonitor, which artificially implant group policy objects into the registry to block rogue programs such as Dqb ransomware.

Note that Windows 10 Fall Creators Update includes a "Controlled Folder Access" feature that blocks ransomware attempts to encrypt your files. By default, this feature automatically protects files stored in Documents, Pictures, Videos, Music, Favorites as well as Desktop folders.

Controll Folder Access

Windows 10 users should install this update to protect their data from ransomware attacks. Here is more information on how to get this update and add an additional protection layer from ransomware infections.

HitmanPro.Alert CryptoGuard - detects encryption of files and neutralises any attempts without need for user-intervention:

hitmanproalert ransomware prevention application

Malwarebytes Anti-Ransomware Beta uses advanced proactive technology that monitors ransomware activity and terminates it immediately - before reaching users' files:

malwarebytes anti-ransomware

  • The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups. More information on online backup solutions and data recovery software Here.

Other tools known to remove Dqb ransomware:

About the author:

Tomas Meskauskas

Tomas Meskauskas - expert security researcher, professional malware analyst.

I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats. Contact Tomas Meskauskas.

PCrisk security portal is brought by a company RCS LT. Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.

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Malware activity

Global virus and spyware activity level today:

Medium threat activity

Increased attack rate of infections detected within the last 24 hours.

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Dqb virus QR code
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Platform: Windows

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