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  • Active
  • Severity: High
  • Ransomware
  • Windows
  • Verified · Apr 2021

How to remove GandCrab v4 ransomware

A step-by-step removal guide for affected devices. Follow the verified procedure below — most readers complete it in under 10 minutes.

Gabriel E. Hall · Passionate web researcher

GandCrab v4 ransomware – the dangerous file locking virus that came back with its 4th version

GandCrab v4 virus

GandCrab v4 ransomware is the newest variant of the GandCrab family and was first noticed by security experts[1] at the start of July 2018. This crypto-virus uses AES-256 (CBC mode) and RSA-2048 encryption algorithm to encrypt data and then adds .KRAB appendix to each of the affected files. As a result, this version has been dubbed as KRAB ransomware. Soon after the encryption is finished, the malware drops a ransom note CRAB-DECRYPT.txt or KRAB-DECRYPT.txt which explains to users that the only way to recover data is to pay cybercriminals in Bitcoin cryptocurrency. Security experts found evidence that Romanian-born hackers created the newest variant of the virus.

SUMMARY
Name GandCrab v4
Type Ransomware
Associated with GandCrab family
Further versions
  • GandCrab 4.1;
  • GandCrab 4.2.
Encryption algorithm AES-256 and RSA-2048
File extension .KRAB
Ransom note CRAB-DECRYPT.txt or KRAB-DECRYPT.txt
Elimination Automatic only – use FortectIntego, SpyHunterCombo Cleaner or MalwarebytesMalwarebytes
Decryption Use a free GandCrab v4 decryptor by Bitdefender

Although crooks behind previous versions of malware were stopped and file-decrypting tool was created, it is still not the case with GandCrab v4 virus. As the cyber threat showed up in summer 2018, security researchers from Bitdefender have already developed the free decryptor for this threat which you can find in our data recovery guide. Nevertheless, the first step to normal computer operation is GandCrab v4 ransomware removal.

The crypto-malware usually infiltrates machines via contaminated file attachments in spam e-mails, breaks in through a poorly protected RDP,[2] using software vulnerabilities or via executables found on malicious websites (such as file-sharing or torrent sites). As soon as GandCrab v4 virus enters, it performs a full system scans, looking for files to encrypt. After that, it appends the .KRAB extension to all video, audio, photo, database, image files. Therefore, a picture.jpg is modified to picture.jpg.KRAB and becomes inaccessible.

The key that could unlock files is located on a server which is only reachable to GandCrab v4 cybercrooks. The worst part is that each of the keys is generated separately for each of the infected computers, making it impossible to re-use it. Nevertheless, security researchers[3] do not recommend paying ransom under any circumstances.

Hackers are known to ignore victims and never send the promised key. Additionally, the bad actors could instead send more malware which could inflict further damage to your machine. Therefore, do not panic if KRAB extension locks your files. Simply download and install FortectIntego, SpyHunterCombo Cleaner, MalwarebytesMalwarebytes or any other reputable security software and run a full system scan. This will help you to remove GandCrab v4 ransomware effectively.

Only after elimination procedure, you can attempt file recovery. Unfortunately, the only safe way to get your files back is by using backups (either by using cloud services or a physical external storage device, such as USB stick or an external HDD). Thus, even if you do not think that you could get infected, still back-up your data regularly, as it can save your precious files from destruction.

GandCrab v4 ransomware

Avoid opening emails that look or feel suspicious

Contaminated attachments in phishing emails are usually the main culprit of the ransomware infection. Hackers often abuse the fact that users are careless when it comes to computer safety and employ bots to send out thousands of spam emails that may look very believable. As soon as the victim clicks on the malicious attachment, the payload of the virus is executed, and all files are locked. To avoid that, carefully examine emails and do not click any links or on the attachments if you are not 100% sure that they are legitimate.

Other ways dangerous malware can be injected into the machine include:

  • Exploit kits;
  • Unprotected RDP;
  • Using botnets;
  • Infected executable files on file-sharing sites and P2P networks;
  • Cracked or re-packed software;
  • Fake updates, etc.

Remove GandCrab v4 using reputable security software

To remove GandCrab V4 virus safely, you need to employ anti-malware software. Having a reputable security tool installed is mandatory if you want to protect yourself from dangers online. However, if you are still not using any protection, your computer is in imminent danger. Thus, download FortectIntego, SpyHunterCombo Cleaner or MalwarebytesMalwarebytes and bring it up to date. If malware is preventing from proper anti-virus program operation, enter Safe Mode with Networking, as explained below.

Only after full GandCrab v4 removal, you can attempt to recover your files. Otherwise, they will get encrypted again. Therefore, if you own a backup of your data, DO NOT CONNECT the device (external drive or similar) before the virus is eliminated. If you do not have a backup, you can try recovering your files by using decryption software provided below.

A video below explains how to create a safe environment before you start deleting GandCrab. Keep in mind that the virus is capable of disabling legitimate security software to prevent its removal from the system. To prevent serious consequences hailing from such ability, you should perform these steps:

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