Bk666 Ransomware

Also Known As: Bk666 virus
Distribution: Low
Damage level: Severe

Bk666 ransomware removal instructions

What is Bk666?

Discovered by Jakub Kroustek, Bk666 is yet another ransomware-type virus that belongs to the Dharma ransomware family. After successful infiltration, Bk666 encrypts most stored data, thereby making it unusable. Furthermore, Bk666 renames each file by adding the ".bk666" extension plus the victim's unique ID and developer's email address. For example, "sample.jpg" is renamed to a filename such as "sample.jpg.id-1E857D00.[berserk666@tutanota.com].bk666". Once data is encrypted, Bk666 places a text file ("FILES ENCRYPTED.txt") on the desktop and opens a pop-up window.

As with all variants of Dharma, Bk666's text file delivers a message informing victims of the encryption and encouraging them to contact the developers. The pop-up window provides a little more information. It states that data can only be encrypted using a decryption key and tool. Each victim receives a unique decryption key. To acquire this tool and restore files, victims must pay a ransom. The cost is not specified but supposedly depends on how quickly victims make contact with these people. Nevertheless, criminals usually demand $500-$1500 in Monero, Ethereum, Bitcoin, or another cryptocurrency. Bk666's developers allow victims to attach one selected file (up to 1 MB, non-archived), which is restored and returned as a 'guarantee' that decryption is possible and that these people can be trusted. In fact, research shows that many cyber criminals cannot be trusted - victims are often ignored and scammed once payments are submitted. Therefore, we strongly advise you to ignore all requests to submit payments or contact these people. Unfortunately, there are no tools capable of cracking Bk666 encryption and restoring data free of charge. The only solution is to restore everything from a backup.

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

Bk666 decrypt instructions

Bk666 is regular ransomware, and thus shares many similarities with dozens of other ransomware-type infections, including P3rf0rm4, Metan, and Robbinhood. Although the developers are different, these ransomware infections have virtually identical behavior - they compromise data and make ransom demands. They usually employ RSA, AES, and other similar cryptographies that generate unique decryption keys. Therefore, unless the virus is still in development or has certain bugs/flaws, restoring data manually without involvement of developers (contacting these people is not recommended) is impossible. Viruses such as Bk666 are one of the main reasons why you should maintain regular backups, however, restore them on an unplugged storage device (e.g., external hard drive, Flash drive, or similar) or remote server (e.g., Cloud), since locally stored backups are encrypted with regular data.

Bk666 ransomware technical analysis:

  • Detection names: Avast (Win32:Trojan-gen), BitDefender (MemScan:Trojan.Agent.DSDW), Kaspersky (HEUR:Trojan.Win32.Generic), ESET-NOD32 (a variant of Win32/Packed.Themida.EFP)
  • Full list of antivirus detections: VirusTotal
  • Executable filename: exp1mod.exe
  • Sample first submitted: 2019-03-22

How did ransomware infect my computer?

The method by which developers proliferate Bk666 is currently unknown, however, ransomware is generally distributed using fake software updaters/cracks, trojans, spam email campaigns, and unofficial software download sources. Fake updaters infect computers by exploiting outdated software bugs/flaws or simply downloading and installing malware rather than updates. Cracking tools bypass paid software activation, however, criminals use them to proliferate malware, and thus users often end up infecting their computers, rather than gaining access to paid features. Trojans are infectious applications that infiltrate computers and continue to inject additional malware. Spam campaigns are used to send thousands of emails with malicious attachments and deceptive messages encouraging users to open them. In doing so, users expose their systems to risk of various infections. Third party software download sources are also an issue. Developers proliferate malicious executables by presenting them as legitimate software. In this way, users are tricked into downloading and installing malware. In summary, the main reasons for computer infections are poor knowledge of these threats and careless behavior.

Threat Summary:
Name Bk666 virus
Threat Type Ransomware, Crypto Virus, Files locker.
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 a ransom payment (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 Bk666 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?

To prevent this situation, be very cautious when downloading, installing, updating software, and browsing the internet in general. Download apps from official sources only, using direct download links. Third party downloaders/installers often include rogue apps, and thus these tools should never be used. Similar rules apply to software updates. It is important to keep installed apps and operating systems up-to-date, however, employ only implemented functions or tools provided by the official developer. Never attempt to crack installed software, since software piracy is a cyber crime and the risk of infections is extremely high. Furthermore, be very careful when opening email attachments. Files/links that are irrelevant and those received from suspicious/unrecognizable email addresses should never be opened. These emails should be deleted without reading. Have a reputable anti-virus/anti-spyware suite installed and running. These tools can detect and eliminate malware before the system is harmed. Caution is the key to computer safety. If your computer is already infected with Bk666, we recommend running a scan with Spyhunter for Windows to automatically eliminate this ransomware.

Text presented in Bk666 ransomware pop-up window:

All your files have been encrypted!
All your files have been encrypted due to a security problem with your PC. If you want to restore them, write us to the e-mail berserk666@tutanota.com
Write this ID in the title of your message 1E857D00
In case of no answer in 24 hours write us to theese e-mails:berserk666@cock.li
You have to pay for decryption in Bitcoins. The price depends on how fast you write to us. After payment we will send you the decryption tool that will decrypt all your files.
Free decryption as guarantee
Before paying 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.)
How to obtain Bitcoins
The easiest way to buy bitcoins is LocalBitcoins site. You have to register, click 'Buy bitcoins', and select the seller by payment method and price.
Also you can find other places to buy Bitcoins and beginners guide here:
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 Bk666 text file ("FILES ENCRYPTED.txt"):

Bk666 text file

Text presented within this file:

all your data has been locked us
You want to return?
write email berserk666@tutanota.com or berserk666@cock.li

Screenshot of files encrypted by Bk666 (".bk666" extension):

Files encrypted by Bk666

Bk666 ransomware removal:

Instant automatic removal of Bk666 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 Bk666 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 Bk666 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 Bk666 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 Bk666 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 Bk666 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 Bk666, 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 Bk666 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 the 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 Bk666 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 pcrisk.com 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.

QR Code
Bk666 virus QR code
A QR code (Quick Response Code) is a machine-readable code which stores URLs and other information. This code can be read using a camera on a smartphone or a tablet. Scan this QR code to have an easy access removal guide of Bk666 virus on your mobile device.
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Platform: Windows

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