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GANDCRAB V4 Ransomware – Remove and Restore .KRAB Encrypted Files

This article has been written with the main goal of helping you understand what is the GANDCRAB V4 ransomware virus and how to effectively remove it from your PC plus how you can attempt to recover .KRAB files, encrypted by this iteration.

GANDCRAB has successfully come out in a new version, using the .KRAB file extension. With this new version, the ransomware virus, demanding victims to pay the ransom in the DASH cryptocurrency, has become one of the biggest ransomware viruses alongside big ransomware families like WannaCry, Dharma, CryptoWall and CryptoLocker. The main purpose of .KRAB this version of GANDCRAB is to encrypt your data. Typically, the ransomware drops a ransom note file, called KRAB-DECRYPT.txt, which aims to extort victims to pay a ransom “fee” to get the files to work again. If your computer has been infected by the GANDCRAB V4 ransomware virus, we strongly suggest that you read this article and learn how you can remove this malware effectively and how you can try and recover as many .KRAB encrypted files as possible, without paying the ransom.

Threat Summary

Name GANDCRAB V4
Type Ransomware, Cryptovirus
Short Description New version of GandCrab ransomware. Encrypts the files, making them unable to be opened and asks victims to pay ransom in the DASH cryptocurrency to get the files to work again.
Symptoms The GANDCRAB V4 virus leaves the files with the .KRAB file extension and drops a ransom note, called KRAB-DECRYPT.txt.
Distribution Method Spam Emails, Email Attachments, Executable files
Detection Tool See If Your System Has Been Affected by malware

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User Experience Join Our Forum to Discuss GANDCRAB V4.
Data Recovery Tool Windows Data Recovery by Stellar Phoenix Notice! This product scans your drive sectors to recover lost files and it may not recover 100% of the encrypted files, but only few of them, depending on the situation and whether or not you have reformatted your drive.

GandCrab Ransomware – Update December 2018

GandCrab ransomware has continued to evolve into a 5.0.9 version, which was discovered in the beginning of December 2018. More information about it can be found on the following related story:

Related: [wplinkpreview url=”https://www.sensorstechforum.com/remove-gandcrab-v5-0-9-cryptovirus/”]Remove GANDCRAB v5.0.9 Cryptovirus

GANDCRAB V4 Virus – Update November 2018

The v4 release of the Gandcrab ransomware family has been found very effective against IoT devices. The exploit kit and attack configuration parameters used to infect the devices appear to target machines using weak or default account login credentials. Unfortunately many smart device owners do not adhere to the security practice of changing the passwords once they configure their devices. This is the reason why ransomware and malware attacks are very successful against this subset of victim devices.

Web servers and running services can be defaced — user data and content will be deleted and a ransomware note will be displayed. Furthermore through the compromised devices more attacks can be made, especially if they are recruited to a botnet.

GANDCRAB V4 Virus – Update August 2018

The GANDCRAB V4 Virus continues to spread in August, 2018. Malware researchers suspect that more countries might be getting affected as more languages have been added to the payment page of the ransomware. You can clearly see that from the below screenshot:

If more languages are being added, either the cybercriminals are going to spread their malware in more countries (by using malvertising campaigns, for example) or they know that those countries are already affected by the GANDCRAB V4 Virus.

GANDCRAB V4 Virus – How Does It Infect Victims

The infection process of the .KRAB iteration of this ransomware is rather similar to the infection procedure that was used in its older versions. The ransomware authors aim to use a malicious attachment, often a Microsoft Office document or a .PDF file, whose main goal is to trick users to enable Macros. Such documents often deceive users that, unless editing is not enabled, they cannot read what is in the documents. One such file was detected by researcher Marcelo Rivero to be a receipt in a PDF file which then leads to infecting the user with GANDCRAB V4. The infection chain occurs as it follows:

The e-mails carrying the ransomware are spreading the attachment in a .7z archive file with the same name as the PDF document inside, as researcher from malware-traffic-analysis Brad has discovered. The messages in the e-mails themselves aim to convince the user that the attachment is of utmost importance and should be opened immediately. Below, you can see one of the e-mails carrying a malicious GANDCRAB attachment:

From: Deanna Bennett <>
Subject: Payment Invoice #93611
Attachment: DOC402942349491-PDF.7Z

Dear Customer,
To read your document please open the attachment and reply as soon as possible.
Kind regards,
TCR Customer Support

Naturally, there are other subjects and other e-mails as well, since the cyber-criminals who are behind GANDCRAB V4 have likely created a lot of e-mail templates in order to avoid having their e-mail addresses flagged by the e-mail providers’ detection software. Here are some of the topics (subjects) you are likely to encounter in an e-mail, carrying GANDCRAB V4 ransomware virus:

Document #72170
Invoice #21613
Order #87884
Payment #72985
Payment Invoice #58058
Payment Invoice #93611
Ticket #07009
Your Document #78391
Your Order #16323
Your Ticket #23428

In addition to documents with malicious Macros, the GANDCRAB V4 ransomware may also infect you by simply clicking on the .7z file, since researchers have reported that the malware may self-extract a .JS (JavaScript) file with the same name which automatically starts the infection process:

GANDCRAB V4 Ransomware – Analysis

Once the malicious .JS file or the malicious macros that cause the infection with GANDCRAB V4 ransomware are executed, the ransomware virus begins its malicious activities. The .JS file drops an executable type of fil, which is often named randomly or resembles a legitimate Windows program. The location in which this file is dropped may be the the following:

→ C:\Users\{Your Username}\AppData\{malicious file name}.exe
HASH of the file: 97a910c50171124f2cd8cfc7a4f2fa4f

Then, the virus uses the “RunOnce” registry sub-key in which it adds the REG_SZ type of registry value. This is done with the purpose of getting the malicious file to run automatically on Windows boot. This procedure may result in the ransomware .exe running automatically on Windows login. The RunOnce subkeys in which you can find the value string have the following locations:

→ HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce

The GANDCRAB V4 ransomware also makes sure that the victim reads its ransom note file, which contains instructions how to download and install Tor browser to anonymously pay the ransom in the DASH cryptocurrency by going on the ransomware’s web page. The note is called by two names – CRAB-DECRYPT.txt or KRAB-DECRYPT.txt and has the following message for the victims to see:

–= GANDCRAB V4 =—
Attention!
All your files, documents, photos, databases and other important files are encrypted and have the extension: .KRAB
The only method of recovering files is to purchase an unique private key. Only we can give you this key and only we can recover your files.
The server with your key is in a closed network TOR. You can get there by the following ways:
—————————————————————————————-
| 0. Download Tor browser – https://www.torproject.org/
| 1. Install Tor browser
| 2. Open Tor Browser
| 3. Open link in TOR browser:
| 4. Follow the instructions on this page
—————————————————————————————-
On our page you will see instructions on payment and get the opportunity to decrypt 1 file for free.
ATTENTION!
IN ORDER TO PREVENT DATA DAMAGE:
* DO NOT MODIFY ENCRYPTED FILES
* DO NOT CHANGE DATA BELOW
—BEGIN GANDCRAB KEY—
—END GANDCRAB KEY—
—BEGIN PC DATA—
—END PC DATA—

When the victim opens the web page in Tor browser, a similar web page to the other GANDCRAB variants is also seen with this version:

The web page also features a live chat and detailed instructions on how to pay the ransom to get the so-called GandCrab Decryptor:

GANDCRAB V4 Ransomware – Encryption Process

GANDCRAB ransomware uses a very sophisticated and well-developed encryption procedure which utilizes the combination of the following encryption algorithms:

  • AES-256 (Advanced Encryption Standard)
  • RSA-2048 (Rivest-Shamir-Adleman)

Both of the ciphers are respectively in the 256 bit and 2048 bit of strength, making them impossible to be decoded if you do not know the decryption keys. And to further complicate the situation, GANDCRAB V4 ransomware also encrypts the files in something known as CBC mode, or Cipher-Block Chaining mode. This mode chains up the encrypted files in a way that is tamper-proof. To best explain this, GANDCRAB V4 encrypts the files as it follows:

Step 1: The ransomware scans for the files it wants to encrypt (documents, videos, images, audio files, archives, etc.), while excluding files in Windows directories that may damage the functioning of your PC.
Step 2: GANDCRAB V4 encrypts the files by creating copies of the original files, which are with replaced blocks of data within them. The bad news is that the CBC mode links those blocks together and if the files are tampered with, the CBC mode breaks them indefinitely.
Step 3: After encryption, the ransomware generates a unique decryption key for each file; all files are likely linked in a KEY file, which is also encrypted, making it impossible to decrypt the files without the decryption key.
Step 4: GANDCRAB V4 ransomware adds the .KRAB file suffix to the encrypted copies of the files and deletes the original files. This makes the encrypted files to appear like the following:

Step 5: The virus likely triggers the following commands as an administrator in Windows Command Prompt:

→ sc stop VVS
sc stop wscsvc
sc stop WinDefend
sc stop wuauserv
sc stop BITS
sc stop ERSvc
sc stop WerSvc
cmd.exe /C bcdedit /set {default} recoveryenabled No
cmd.exe /C bcdedit /set {default} bootstatuspolicy ignoreallfailures
C:\Windows\System32\cmd.exe” /C vssadmin.exe Delete Shadows /All /Quiet

This is done with the purpose to delete the shadow volume copies of the infected machine, so that the user cannot restore the files, using Windows Recovery.

Remove GANDCRAB V4 Ransomware and Restore .KRAB Encrypted Files

Removing GANDCRAB V4 ransomware may be more complicated than it seems, since this ransomware virus may contain multiple defensive techniques that may damage your files and your computer indefinitely. One way to remove the ransomware manually is if you follow the manual removal instructions underneath this article and use the information to do the removal yourself. Keep in mind you must really know what you are doing, since you risk loosing your files indefinitely.

Another way to do the removal, which is often advised by security analysts, is to download and install an advanced anti-malware software. Such program will automatically scan for and remove all of the GANDCRAB V4-related virus files and make sure that the virus is safely removed from your computer.

If you want to restore your encrypted files, directly trying to decrypt them is not a good idea, unless there is an official decryptor available. Paying the ransom is one way to go with, but it is not advisable, mainly because you may not get your files after paying. By paying, you are also supporting the operation of the cyber-criminals as well. Thus, we suggest that you try out the alternative methods for file recovery underneath this article in step “2. Restore files, encrypted by GANDCRAB V4”. They have been created to help you try and restore the deleted original files by GANDCRAB V4 by using data recovery software to recover some or most of your files, depending on the condition of the deleted file. The methods are not 100% effective to recover your data, but their main goal is to help you to restore as many files as possible, as they have helped some of the users on our forums.

Avatar

Ventsislav Krastev

Ventsislav is a cybersecurity expert at SensorsTechForum since 2015. He has been researching, covering, helping victims with the latest malware infections plus testing and reviewing software and the newest tech developments. Having graduated Marketing as well, Ventsislav also has passion for learning new shifts and innovations in cybersecurity that become game changers. After studying Value Chain Management, Network Administration and Computer Administration of System Applications, he found his true calling within the cybersecrurity industry and is a strong believer in the education of every user towards online safety and security.

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Attention! SensorsTechForum strongly recommends that all malware victims should look for assistance only by reputable sources. Many guides out there claim to offer free recovery and decryption for files encrypted by ransomware viruses. Be advised that some of them may only be after your money.

As a site that has been dedicated to providing free removal instructions for ransomware and malware since 2014, SensorsTechForum’s recommendation is to only pay attention to trustworthy sources.

How to recognize trustworthy sources:

  • Always check "About Us" web page.
  • Profile of the content creator.
  • Make sure that real people are behind the site and not fake names and profiles.
  • Verify Facebook, LinkedIn and Twitter personal profiles.


OFFER

REMOVE IT NOW (PC)
with Anti-Malware
We recommend you to download SpyHunter and run free scan to remove all virus files on your PC. This saves you hours of time and effort compared to doing the removal yourself.
SpyHunter 5 free remover allows you, subject to a 48-hour waiting period, one remediation and removal for results found. Read EULA and Privacy Policy


Windows Mac OS X

How to Remove GANDCRAB V4 from Windows.


Step 1: Boot Your PC In Safe Mode to isolate and remove GANDCRAB V4

OFFER

Manual Removal Usually Takes Time and You Risk Damaging Your Files If Not Careful!
We Recommend To Scan Your PC with SpyHunter

Keep in mind, that SpyHunter’s scanner is only for malware detection. If SpyHunter detects malware on your PC, you will need to purchase SpyHunter's malware removal tool to remove the malware threats. Read our SpyHunter 5 review. Click on the corresponding links to check SpyHunter's EULA, Privacy Policy and Threat Assessment Criteria

1. Hold Windows key() + R


2. The "Run" Window will appear. In it, type "msconfig" and click OK.


3. Go to the "Boot" tab. There select "Safe Boot" and then click "Apply" and "OK".
Tip: Make sure to reverse those changes by unticking Safe Boot after that, because your system will always boot in Safe Boot from now on.


4. When prompted, click on "Restart" to go into Safe Mode.


5. You can recognise Safe Mode by the words written on the corners of your screen.


Step 2: Uninstall GANDCRAB V4 and related software from Windows

Here is a method in few easy steps that should be able to uninstall most programs. No matter if you are using Windows 10, 8, 7, Vista or XP, those steps will get the job done. Dragging the program or its folder to the recycle bin can be a very bad decision. If you do that, bits and pieces of the program are left behind, and that can lead to unstable work of your PC, errors with the file type associations and other unpleasant activities. The proper way to get a program off your computer is to Uninstall it. To do that:


1. Hold the Windows Logo Button and "R" on your keyboard. A Pop-up window will appear.


2. In the field type in "appwiz.cpl" and press ENTER.


3. This will open a window with all the programs installed on the PC. Select the program that you want to remove, and press "Uninstall"
Follow the instructions above and you will successfully uninstall most programs.


Step 3: Clean any registries, created by GANDCRAB V4 on your computer.

The usually targeted registries of Windows machines are the following:

  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce

You can access them by opening the Windows registry editor and deleting any values, created by GANDCRAB V4 there. This can happen by following the steps underneath:

1. Open the Run Window again, type "regedit" and click OK.


2. When you open it, you can freely navigate to the Run and RunOnce keys, whose locations are shown above.


3. You can remove the value of the virus by right-clicking on it and removing it.
Tip: To find a virus-created value, you can right-click on it and click "Modify" to see which file it is set to run. If this is the virus file location, remove the value.

IMPORTANT!
Before starting "Step 4", please boot back into Normal mode, in case you are currently in Safe Mode.
This will enable you to install and use SpyHunter 5 successfully.

Step 4: Scan for GANDCRAB V4 with SpyHunter Anti-Malware Tool

1. Click on the "Download" button to proceed to SpyHunter's download page.


It is recommended to run a scan before purchasing the full version of the software to make sure that the current version of the malware can be detected by SpyHunter. Click on the corresponding links to check SpyHunter's EULA, Privacy Policy and Threat Assessment Criteria.


2. After you have installed SpyHunter, wait for it to update automatically.

SpyHunter5-update-2018


3. After the update process has finished, click on the 'Malware/PC Scan' tab. A new window will appear. Click on 'Start Scan'.

SpyHunter5-Free-Scan-2018


4. After SpyHunter has finished scanning your PC for any files of the associated threat and found them, you can try to get them removed automatically and permanently by clicking on the 'Next' button.

SpyHunter-5-Free-Scan-Next-2018

If any threats have been removed, it is highly recommended to restart your PC.

Step 5 (Optional): Try to Restore Files Encrypted by GANDCRAB V4.

Ransomware infections and GANDCRAB V4 aim to encrypt your files using an encryption algorithm which may be very difficult to decrypt. This is why we have suggested a data recovery method that may help you go around direct decryption and try to restore your files. Bear in mind that this method may not be 100% effective but may also help you a little or a lot in different situations.

1. Download the reccomended Data Recovery software by clicking on the link underneath:

Simply click on the link and on the website menus on top, choose Data Recovery - Data Recovery Wizard for Windows or Mac (depending on your OS), and then download and run the tool.


Windows Mac OS X

Get rid of GANDCRAB V4 from Mac OS X.


Step 1: Uninstall GANDCRAB V4 and remove related files and objects

OFFER
Manual Removal Usually Takes Time and You Risk Damaging Your Files If Not Careful!
We Recommend To Scan Your Mac with SpyHunter for Mac
Keep in mind, that SpyHunter for Mac needs to purchased to remove the malware threats. Click on the corresponding links to check SpyHunter’s EULA and Privacy Policy


1. Hit the ⇧+⌘+U keys to open Utilities. Another way is to click on “Go” and then click “Utilities”, like the image below shows:


2. Find Activity Monitor and double-click it:


3. In the Activity Monitor look for any suspicious processes, belonging or related to GANDCRAB V4:

Tip: To quit a process completely, choose the “Force Quit” option.


4. Click on the "Go" button again, but this time select Applications. Another way is with the ⇧+⌘+A buttons.


5. In the Applications menu, look for any suspicious app or an app with a name, similar or identical to GANDCRAB V4. If you find it, right-click on the app and select “Move to Trash”.


6: Select Accounts, after which click on the Login Items preference. Your Mac will then show you a list of items that start automatically when you log in. Look for any suspicious apps identical or similar to GANDCRAB V4. Check the app you want to stop from running automatically and then select on the Minus (“-“) icon to hide it.


7: Remove any left-over files that might be related to this threat manually by following the sub-steps below:

  • Go to Finder.
  • In the search bar type the name of the app that you want to remove.
  • Above the search bar change the two drop down menus to “System Files” and “Are Included” so that you can see all of the files associated with the application you want to remove. Bear in mind that some of the files may not be related to the app so be very careful which files you delete.
  • If all of the files are related, hold the ⌘+A buttons to select them and then drive them to “Trash”.

In case you cannot remove GANDCRAB V4 via Step 1 above:

In case you cannot find the virus files and objects in your Applications or other places we have shown above, you can manually look for them in the Libraries of your Mac. But before doing this, please read the disclaimer below:

Disclaimer! If you are about to tamper with Library files on Mac, be sure to know the name of the virus file, because if you delete the wrong file, it may cause irreversible damage to your MacOS. Continue on your own responsibility!

1: Click on "Go" and Then "Go to Folder" as shown underneath:

2: Type in "/Library/LauchAgents/" and click Ok:

3: Delete all of the virus files that have similar or the same name as GANDCRAB V4. If you believe there is no such file, do not delete anything.

You can repeat the same procedure with the following other Library directories:

→ ~/Library/LaunchAgents
/Library/LaunchDaemons

Tip: ~ is there on purpose, because it leads to more LaunchAgents.


Click the button below below to download SpyHunter for Mac and scan for GANDCRAB V4:


Download

SpyHunter for Mac



Step 3 (Optional): Try to Restore Files Encrypted by GANDCRAB V4.

Ransomware infections and GANDCRAB V4 aim to encrypt your files using an encryption algorithm which may be very difficult to decrypt. This is why we have suggested a data recovery method that may help you go around direct decryption and try to restore your files. Bear in mind that this method may not be 100% effective but may also help you a little or a lot in different situations.

1. Download the reccomended Data Recovery software by clicking on the link underneath:

Simply click on the link and on the website menus on top, choose Data Recovery - Data Recovery Wizard for Windows or Mac (depending on your OS), and then download and run the tool.


GANDCRAB V4 FAQ

What is GANDCRAB V4 ransomware and how does it work?

GANDCRAB V4 is a ransomware infection - the malicious software that enters your computer silently and blocks either access to the computer itself or encrypt your files.

Many ransomware viruses use sophisticated encryption algorithm how to make your files inaccessible. The goal of ransomware infections is to demand that you pay a ransom payment to get access to your files back.

How does GANDCRAB V4 ransomware infect my computer?

Via several ways.GANDCRAB V4 Ransomware infects computers by being sent via phishing e-mails, containing virus attachment.

This attachment is usually masked as an important document, like an invoice, bank document or even a plane ticket and it looks very convincing to users.

After you download and execute this attachment, a drive-by download occurs and your computer is infected with the ransomware virus.

Another way, you may become a victim of GANDCRAB V4 is if you download a fake installer, crack or patch from a low reputation website or if you click on a virus link. Many users report getting a ransomware infection by downloading torrents.

How to open .GANDCRAB V4 files?

You can't. At this point the .GANDCRAB V4 files are encrypted. You can only open them once they are decrypted.

Decryptor did not decrypt my data. What now?

Do not panic and backup the files. If a decryptor did not decrypt your .GANDCRAB V4 files successfully, then do not despair, because this virus is still new.

One way to restore files, encrypted by GANDCRAB V4 ransomware is to use a decryptor for it. But since it's a new virus, advised that the decryption keys for it may not be out yet and available to the public. We will update this article and keep you posted as soon as this decryptor is released.

How Do I restore ".GANDCRAB V4" files (Other Methods)?

Yes, sometimes files can be restored. We have suggested several file recovery methods that could work if you want to restore .GANDCRAB V4 files.

These methods are in no way 100% guarantee that you will be able to get your files back. But if you have a backup, your chances of success are much greater.

How do I get rid of GANDCRAB V4 ransomware virus?

The safest way and the most efficient one for the removal of this ransomware infection is the use a professional anti malware software. It will scan for and locate GANDCRAB V4 ransomware and then remove it without causing any additional harm to your important .GANDCRAB V4 files.

Also, keep in mind that viruses like GANDCRAB V4 ransomware also install Trojans and keyloggers that can steal your passwords and accounts. Scanning your computer with an anti-malware software will make sure that all of these virus components are removed and your computer is protected in the future.

What to Do If nothing works?

There is still a lot you can do. If none of the above methods seem to work for you, then try these methods:

  • Try to find a safe computer from where you can can login on your own line accounts like One Drive, iDrive, Google Drive and so on.
  • Try to contact your friends, relatives and other people so that they can check if they have some of your important photos or documents just in case you sent them.
  • Also, check if some of the files that were encrypted it can be re-downloaded from the web.
  • Another clever way to get back some of your files is to find another old computer, a flash drive or even a CD or a DVD where you may have saved your older documents. You might be surprised what will turn up.
  • You can also go to your email account to check if you can send any attachments to other people. Usually what is sent the email is saved on your account and you can re-download it. But most importantly, make sure that this is done from a safe computer and make sure to remove the virus first.

More tips you can find on our forums, where you can also asks any questions about your ransomware problem.

4 Comments
  1. AvatarLynne

    I have a battery symbol in the top right corner of my phone. It is not the life of the battery it has what looks like 3 triangles in it. It appeared about a week ago. Please can you help.

    Reply
  2. Avataranonimo

    es el ahorro de datos, saludos

    Reply
  3. AvatarMohammad Yari

    My files are encrypted by gandcrab’s ransomware and there is currently no way to access my data. Dear custodians, I ask you to help in solving this problem. If I can not retrieve my elephants, I might lose my job. That’s why I ask for help from all of you.

    Reply
  4. Avatarricardo

    meus amigos estou numa sinuca de bico, é isso mesmo, meus arquivos estão tds criptografados .krab e tenho um studio com trabalhos de clientes diversos e não consigo acessar mais nada e estou aqui a ponto de enlouquecer pq já procurei em tds os locais que era possivel na internet e não existe uma forma de resolver isso, se estiver alguém que possa me ajudar ficarei muito agradecido com isso,
    se aguém puder ajudar agradeço desde já…

    [SensorsTechForum: comment has been edited, personal information was removed from it]

    Reply

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