GandCrab ransomware: what it is and how to remove it

From our report of Jun 2021 · not reviewed since

More from our earlier report on GandCrab

• While the malware is one of the most devastating threats currently, Bitdefender research team, while working with Europol and Romanian police, managed to create the 3rd decryptor that works for versions 1, 4, 5.0.1 through 5.1.
• GDCB-DECRYPT.txt; KRAB-DECRYPT.txt; krab-decrypt.txt, -DECRYPT.html, [victim's ID]-DECRYPT.txt, [victim's ID]-DECRYPT.html
• Additionally, you can also try an alternative tool.
• After you get rid of ransomware using security program, fix damaged system components with
• In the beginning, after two months of active distribution, the first versions of ransomware were defeated by the Romanian police, experts from Bitdefender, and Europol.
• After revealing the flaw in the ransomware code, authorities hacked cybercriminals, and Bitdefender created a free decryptor available on the NoMoreRansom project.
• The improved versions 5.0.4 and 5.1 haven't been decrypted because hackers patched the critical flaw within 24 hours after the Bitdefender decryptor was released.
• Our outsourced IT, Protek Support, received a ransomware on their master server affecting all their 80 clients including us yesterday morning.
• They've paid the ransom this morning about 7 am, but we are still waiting to get our files decrypted and it's already 4:45 pm.
• It is on our server and only we can recover your files.
• Open link in tor browser: http://gdcbghvjyqy7jclk.onion/ 5.
• Do not try to modify files or use your own private key - this will result in the loss of your data forever!
• Hi All, Please find bеlow the Uр tо date еmеrgency exit maр.
• Please see Emergency exit map in the attachment..
• New variants are detected almost every month.

From our report of Jun 2021 · not reviewed since

GandCrab ransomware is one of the most prolific ransomware viruses worldwide, but most of its versions can be decrypted now

GandCrab ransomware is an infamous family of cryptoviruses that was first introduced in early 2018.

Within a year, it has earned a name as one of the most destructive cyber infections in the world.

The family consists of numerous variants, such as GDCB, KRAB, CRAB virus, etc. All these versions are using RSA 2048 and AES 256 algorithms to encode data and are appending a random and unique file extension to mark doomed victim's data. At the moment of writing, the most aggressive versions are 5.0.4 and 5.1.

The ransomware has been using an array of various distribution methods, including RIG, GradSoft, Magnitude, and Fallout exploit kits, cracks, keygens, and fake updates.

However, it seems that virus developers are not likely to give up. During the first months of 2019, they presented several new versions demanding the 2000 USD ransom in Dash or Bitcoin in exchange for the decryption key.

At the moment, the virus is appending . file extension. Additionally, the victim is given a Tor address to buy the so-called Gandcrab Decryptor from virus creators. However, you should be careful when dealing with hackers because making a payment does not guarantee that you will get the key that you need. The quote from one of the latest victims reveals that you can be left with nothing:

If you have even the slightest suspicion that you can be infected, make sure you take care of GandCrab removal by using tools like . Additionally, try free decrypters given in the table above. If none of them help, delete the virus to prevent additional data loss. Then, keep your files somewhere in a safe location until the decryptor for your version is released.

From our report of Jun 2021 · not reviewed since

Actions proceeded by ransomware after infecting the system

Following the infiltration, ransomware starts collecting information about its victim, including user name, PC name, OS, and similar data.

Additionally, the virus creates a unique ransom ID and starts encrypting files stored on the system. As a result, the user is no longer able to access encrypted files without a key that is saved in C&C servers and can't be obtained without a ransom.

The entire situation, explaining what happened and what has to be done to recover files, is described in the ransom note, saved in every folder with the encrypted data. The file can be named GDCB-DECRYPT.txt, KRAB-DECRYPT.txt, or [victim's ID]-DECRYPT.txt and should never be deleted if you are willing to buy a decryptor. That's because it should be uploaded to a specially-crafted TOR site.

The first versions were using such message:

Newer variants as displaying the following message to their victims. As you can see, you can't :

Once the victim downloads the Tor browser and clicks the link provided in the ransom note, he/she is led to the attacker's website selling the decryptor. Here, the popup titled "GandCrab authentication" shows up, which starts the procedure by requesting to upload the ransom note at first. That's why cybercriminals are claiming in their ransom note: "Under no circumstances do not delete this file."

Additionally, the official site is "unlocked" and presents payment instructions, the amount of the ransom (approximately $1200), services that can be used to exchange the money to bitcoin or DASH cryptocurrency, the address where the money should be sent to and a possibility to upload one file for free decryption. According to hackers, postponing the payment can double the ransom amount.

We should add that the site is well-designed and unique, filled with cartoons and such features as chat support. However, it seems that you can be banned from the assistance for using harsh language.

It is worth mentioning that ransomware identifies a specific period that should be obeyed to make the transaction, or the amount of the payment will double. However, this is merely an attempt to intimidate the victims and force them to pay the ransom without evaluating other options.

Therefore, we strongly advise you not to follow the rules of the criminals since there are alternative ways to get back access to your files or use the decryptor developed by the experts. For that, you must remove ransomware first.

Experts from NoVirus.uk have already warned affected users that this is a highly dangerous computer virus and should be eliminated with the help of a professional or using a robust antivirus. You can find detailed instructions on how to start the elimination procedure at the end of this article.

Additionally, do NOT try to get rid of the virus by yourself. Such complex ransomware-type infections are designed to hide their presence and disguise as legitimate computer processes. Terminating crucial system files might lead to permanent computer damage and re-appearance of the crypto-malware.

From our report of Jun 2021 · not reviewed since

Exploit kits have been actively used in virus distribution

Hackers have employed numerous tactics to infiltrate computers with ransomware.

However, exploit kits are considered the most sophisticated ones as they can successfully detect and identify system vulnerabilities and then misuse these holes for the attack. Experts note that this ransomware strain has been distributed via the following exploit kits :

The Magnitude Exploit Kit, previously used to spread Magniber ransomware, has mainly been used to spread GandCrab ransomware version 2. The EK renders a fileless technique used to execute the virus, which is encoded using VBScript.Encode/JScript.Encode scrip and injected into memory.

When the payload is being executed, the ransomware roots into the explorer.exe file and forces the PC to reboot. After that, it enables the encryptor and locks files with the unique file extension.

Ransomware has also been distributed via a malvertising campaign known as Seamless. With its help, victims are lead to yet another exploit kit called RIG EK. After detecting system vulnerabilities, it exploits them to infect the targeted system with a file-encrypting virus or another dangerous computer virus.

Additionally, the Fallout exploit kit has been used to distribute the Vidar data stealer, which additionally drops the 5.0.4 payload via its command and control server. This function can be configured by the administrator when configuring the malware initially. Upon further inspection, it seems that malware is distributed via malvertising campaigns and even sold as a product online.

Finally, the virus has also been distributed as a Ransomware-as-a-Service (Raas) on the Russian black web. According to the Check Point, hackers have already collected more than 600,000 USD ransom due to the innovative Affiliate Program. Ransomware developers have been paying the participants from 60% to 70% of ransomware revenue in exchange for 24/7 tech support.

According to researchers, this crypto-malware has almost 100 active affiliates; 80 of these participants have successfully dispersed 700 different samples of the malware. More than 70% of infected PCs are located in the UK and US, so it's dedicated to English-speaking PC users. However, the recent version provides several languages to choose from, including German, Italian, French or Japanese languages.

• Rig EK;
• GrandSoft EK;
• Magnitude EK;
• Fallout EK.

From our report of Jun 2021 · not reviewed since

Other methods used for infecting systems with Ransomware

It is worth knowing that exploit kits are not the only way how ransomware is distributed.

Criminals might take advantage of credulous people and use deceptive spam emails with malicious attachments. Usually, these emails disguise themselves as shopping receipts, invoices, or similar documents from well-known brands and companies. Likewise, naive users open the infected attachments and let the cyber threat in.

The first campaigns relied on the "Receipt Feb-21310 " attachment, using the @cdkconstruction.org suffix. This spam email does not have much information, except points out that "DOC attached," which should never be downloaded to the system.

Otherwise, the .doc file subsequently runs a PowerShell script and creates an exploit file (sct5.txt), which currently affects a 64-bit system. As pointed out by various crypto-malware researchers, the sct5.txt file does not run the ultimate payload of the virus but executes an exploit and runs as a medium for malware to get inside.

The latest Gandcrab 5.1 virus has been actively relying on emergenсy exit maр spam, which reads and includes an attachment named "Emergencyexitmap.doc:"

If you happen to receive such an email, the most important thing is not to enable macros that are typically disabled by software makers. Make sure that the Protected view is enabled and ignore emails from unknown senders.

In January 2019, a new malspam campaign "Love You" was noticed by security researchers that targeted users in Japan. It includes the name of a popular Japanese show business star, along with an emoji presented in the subject line.

The phishing email contains an attachment PICo-[9 digit number]2019-jpg.zip that administers the payload. In addition to 5.1 version, the "Love You" campaign also distributes various other payloads, including XMRig mining malware and Phorpiex worm.

From our report of Jun 2021 · not reviewed since

GDCB file extension virus

GDCB file extension virus is one of the first versions of the virus was detected in January 2018.

It showed up a couple of weeks after the release of the original version. Just like its predecessor, it spreads via infected spam email attachments and runs a payload once the attachment is opened.

The virus has been targeting the most popular files, including but not limited to .doc, .txt, .jpg, .png, .audio, .video, etc. and appending .GDCB file extension to each of them. It creates a GDCB-DECRYPT.txt file on the victim's desktop, which urges to download Tor browser and transmit 1.54 DASH ransom. The amount of the ransom increases if the victim is late to pay it.

From our report of Jun 2021 · not reviewed since

Get GandCrab decryptor for free

Cybersecurity experts at NoMoreRansom.org have already presented a decryptor for v1, v4, and v5.

People who got infected with this cyber threat and find the following extensions can install a free tool to recover their encrypted files without paying the ransom:

• .GDCB
• .CRAB
• .KRAB
• .UKCZA
• .YIAQDG
• .CQXGPMKNR
• .HHFEHIOL

However, having in mind that this virus family has numerous versions, sometimes these decryptors can fail to recover your files.

Before you rush with this procedure, note that the experts recommend installing and using the decryption tool only after getting rid of ransomware first. Otherwise, the ransomware will continue to encrypt data on the victimized computer over and over again. Use only professional security tools to delete ransomware from the system. We strongly advise you use the ones which are provided at the end of this article.

If you are unable to regain access to the compromised information with the official decryption tool, there are alternative methods that might help. For example, only some of the virus versions are designed to delete Shadow Volume Copies, so you can use ShadowExplorer or similar third-party tools to recover at least some of the files.

Additionally, you can fully recover files without paying the ransom by using backups. If you do not have them, you should check our prepared alternative data recovery methods at the end of the article and try the decryptor as well.

Also, note that version 4.1.2 and version 5.1 have two different vaccine apps that can trick the virus into thinking it already has encrypted files on the computer. These apps typically create the special file in advance and, this way, make the ransomware to think it has already encrypted this data.

To protect yourself from GandCrab 4.1.2, get this tool here. However, the virus hasn't been active during the latest period. At the moment of writing, the most active virus is 5.1 which has been relying on numerous techniques to get into the system. To protect yourself from this threat, download the vaccine created by Valthek. (direct link)

From our report of Jun 2021 · not reviewed since

Before you proceed to data recovery, get rid of GandCrab ransomware

If you want to recover compromised files, you must remove GandCrab ransomware first.

Unfortunately, there are not many options on how you can do that.

To fix the system, download professional security software as soon as you notice encrypted files on your computer. After installing one of these apps, run a full system scan and let it terminate this file-encrypting virus. can also be used to fix virus damage done to the Windows system automatically. Unfortunately, these programs have nothing to do with the decryption of encrypted files.

Note that you might not be able to install the malware removal tool at first. For that, you must reboot your computer into Safe Mode with Networking or rely on System Restore.

You can find a step-by-step guide on how to do that and get rid of this ransomware at the end of this article. Additionally, our experts have prepared alternative methods to help you disable this malware and recover files encrypted by ransomware.

[GI=method-1]Rebooting your computer to Safe Mode with Networking is the first step in ransomware elimination procedure.

[GI=method-2]To get rid of this ransomware with the help of System Restore, follow these steps:

This is a great tool for data recovery since it does not require any additional functions enabled on the system. Note that is is also useful if you have lost your files due to a system crash.

Windows Previous Versions Feature helps to recover encrypted files

You can travel back in time with Windows Previous Versions if you have System Restore function enabled before ransomware attack.

Use the available decryption tool

Experts have designed a unique decryption software for GandCrab ransomware. You can get it here. In case it doesn't decrypt specific malware versions, feel free to try alternative recovery methods above.