GandCrab v5.1 ransomware decryptor and removal [Feb 19 upd.]

GandCrab 5.1 continues the evolution of the major ransomware plague, now accommodating faster encryption and still posing an extremely high risk to victims.

[Feb 19, 2019 update – decryptor released!]

1. What is Gandcrab v5.1 ransomware?
2. GandCrab 5.1 ransomware automated decryption and data recovery
3. GandCrab 5.1 ransomware manual removal and file recovery
4. Ransomware Prevention Tips

What is GandCrab 5.1 ransomware?

GandCrab v5.1 is both a run-of-the-mill and exceptional ransomware strain at the same time. Like mainstream crypto viruses out there, it propagates behind a victim’s back, encrypts all valuable data on the infected host, and then demands a certain amount of cryptocurrency for decryption. This is a common practice that’s been feeding cybercriminals for many years on end. What makes this particular malady one of a kind, though, is that it represents a family operated by high-profile attackers boasting outstanding competence in malware distribution, cryptography, and self-anonymization. Having been launched in early 2018, GandCrab has suffered a seizure of Command and Control servers, and recently a release of a free decryptor by a renowned antimalware lab. Yet, it’s still afloat and keeps producing spinoffs.

GandCrab 5.1 can be identified by a number of hallmarks. Similarly to its forerunner GandCrab v5.0.4, it appends a random-looking extension to every encrypted item without changing the filename itself. The length of this suffix varies, but it’s mainly a string of 6-10 characters. Therefore, a spreadsheet Test.xlsx will be renamed to Test.xlsx.hbenfmdmca or something like that. Also, the infection leaves a ransom message whose name includes an uppercase variant of the newly assigned victim-specific extension. It will therefore look similar to HBENFMDMCA-DECRYPT.txt.

The offending code also changes the desktop wallpaper to a warning message as shown in the screenshot.

Speaking of the above-mentioned decryption breakthrough, the tool supports ransomware versions up to GandCrab 5.1 (as of February 2019). The crooks, though, were quick enough to make an overhaul of their crypto implementation in the next ransomware build, eliminating the flaw that allowed the white hats to overcome the cipher in the first place. So, now the victims are face to face with the ruthless digital adversary. The following description of this infection’s modus operandi is, therefore, useful both for those attacked and for the users who want to keep their data safe.

GandCrab 5.1 is doing the rounds in several different ways. The dominating technique remains unaltered – it’s the tried-and-tested spam. The culprits engage the mass-mailing power of a botnet to send rogue emails to numerous users. While the messages proper are safe, the attachments aren’t. Those are typically booby-trapped documents that go with macros whose goal is to fire up a JavaScript code in a surreptitious fashion. This way, the ransomware binary and other components are downloaded onto the computer. One more spreading mechanism that’s gearing up for a rise endangers users who go the slippery slope of foul play with app activation. In this case, the contagion is a crack tool for popular software suites, such as Microsoft Office. The workflow is trivial: a person downloads and launches code masqueraded as a crack solution, which is actually the GandCrab 5.1 binary in disguise. A few seconds elapse, and the ransomware is on board.

Having spotted the bulk of valuable data on the contaminated machine’s HDD and network drives, the perpetrating program locks it down using its enhanced crypto algorithms. A big tweak that took effect in GandCrab 5.1 variant is that the encryption speed has increased. The next thing you know, the names of all personal documents, databases, videos, photos and other important files are stained with a new extension. Again, it’s a random string of characters that’s unique to the specific victim. The frightening desktop wallpaper says, “Encrypted by GandCrab 5.1” and includes a reference to the TXT ransom note. The latter, in its turn, contains a Tor link for the victim to follow, which leads to the payment page. It lists two payment options (via Bitcoin or Dash cryptocurrency), provides the criminals’ BTC wallet address, and additionally displays information on the deadline before the ransom size doubles.

So much for the tactic of GandCrab 5.1. What should the victims do? Unfortunately, a free decryption tool has yet to be released – at least, it’s not available at the time of this writing. Sending the ransom is definitely not in the user’s best interest, because it means the bad guys win. That’s a lot of money, too. The amount can be $800 worth of BTC or DSH, but it can as well reach sums multiple times more than that.

Interestingly, security analysts have recently unearthed the involvement of an intermediary link in the ransom-based file decryption procedures, and it’s not about the RaaS (Ransomware-as-a-Service) model alone. The operators of GandCrab turn out to have enhanced their revenue acquisition practices by adding unethical data recovery companies to the mix. Such firms have been negotiating with the extortionists in order to get “discount” codes for the ransoms, and the crooks are reportedly willing to collaborate.

In case the deal works out, a questionably unscrupulous “partner” will advertise the recovery service across multiple marketing channels, including YouTube and social media. GandCrab 5.1 victims who stumble upon one of such ads may get interested and opt for the assistance. The catch is, the dubious recovery company will ask for a higher ransom than the cybercriminals demand. Furthermore, they will enter the previously obtained “promo” code in an obfuscated section of the support chat available on the GandCrab Tor payment page in order to get an extra 5-20% off.

It means that the black hats sitting at the top of the ransomware food chain get their profit, and so do the unprincipled intermediary companies that charge the victims an additional fee while also benefiting from the discounted size of the ransom. The only losing party in this scenario is the infected user. Under the circumstances, it’s certainly recommended to try some of the best practices of forensic data recovery first without resorting for pseudo help of ne’er-do-wells.

GandCrab 5.1 ransomware automated removal and data recovery

When faced with ransomware like GandCrab 5.1, one of the best shortcuts in terms of removal is to use Combo Cleaner, a lightweight and incredibly effective application with PC security and optimization features under the hood. It detects and thoroughly deletes threats while giving you insights into the overall health of your computer.

This program’s protection power spans modules that forestall all known types of malware, including ransomware and browser hijackers, and take your online security to the next level by blocking phishing sites and other suspicious web pages. Follow these simple steps to eliminate the infection for good:

1. Download Combo Cleaner installer.

Download GandCrab 5.1 remover

^{Combo Cleaner scans your PC with no strings attached, but you’ll have to buy its fully functional version to remove the threats it detects. The disk optimization tools that find large files and duplicates are free to use.}

2. Open the CCSetup.exe file to get started. Several subsequent screens will allow you to make initial customizations so that the program works exactly as you need from the get-go.

3. The installation will be followed by an update of malware signatures. Once this process is through, click the Start Scan button in the left-hand sidebar.

4. Combo Cleaner will then check system locations that are most often polluted by Windows malware. The first scan can take a while to finish.

5. Combo Cleaner will display a system tray notification as soon as the scan is over. Click the Resolve found threats button to view the results.

6. The scan summary shows the names and types of the detected threats as well as their statuses and locations. Click the Remove all threats button and follow further on-screen prompts to get rid of these items.

Data recovery toolkit to the rescue

Some strains of ransomware are known to delete the original files after the encryption routine has been completed. As hostile as this activity appears, it can play into your hands. There are applications designed to revive the information that was obliterated because of malfunctioning hardware or due to accidental removal. The tool called Stellar Data Recovery features this type of a capability and therefore it can be applied in ransom attack scenarios to at least get the most important files back. So use the app to get an idea of what data can be restored and let it do the recovery job. Here is a step-by-step walkthrough:

1. Download and install Stellar Data Recovery.

Download Stellar Data Recovery

2. Open the application, select the types of recoverable files to look for, and click Next.

3. Choose the areas you want the tool to recover from and click the Scan button.

4. Having scanned the specified locations, the program will display a notification about the total amount of recoverable data. Close the dialog and click the Recover button. This will hopefully help you get some of your valuable files back.

GandCrab 5.1 ransomware manual removal and file recovery

Some ransomware strains terminate themselves after completing the encryption job on a computer, but some don’t. Furthermore, the GandCrab 5.1 virus may prevent victims from using popular antimalware tools in order to stay on board for as long as possible. Under the circumstances, it may be necessary to utilize the Safe Mode with Networking or System Restore functionality.

Be advised that even after the ransomware is removed, files will still be encrypted and inaccessible. The malicious code cleanup part, however, is important because it keeps a relapse of the infection from occurring further on and eliminates all opportunistic malware.

Ways of non-ransom recovery of files encrypted by GandCrab 5.1

Cracking the crypto used by this ransom Trojan is more of a science fiction thing rather than an attainable prospect for the masses. This is why the troubleshooting in predicaments of this sort is a matter of two approaches: one is to pay the ransom, which isn’t an option for many victims; and the other is to apply instruments that take advantage of the ransomware’s possible weaknesses. If the latter is your pick, the advice below is a must-try.

Ransomware Prevention Tips

To avoid GandCrab 5.1 ransomware and other file-encrypting infections in the future, follow several simple recommendations:

These techniques are certainly not a cure-all, but they will add an extra layer of ransomware protection to your security setup.

Revise your security status

Post-factum assessment of the accuracy component in malware removal scenarios is a great habit that prevents the comeback of harmful code or replication of its unattended fractions. Make sure you are good to go by running an additional safety checkup. Another benefit of using the antimalware tool is that it will keep ransomware threats from intruding on your computer further on.

Download GandCrab 5.1 removal tool