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GandCrab v5.0.4 ransomware decryptor and removal guide

7 min read
The new GandCrab v5.0.4 variant of the nefarious ransomware strain has been released in quick succession after the precursor, with a few tweaks in effect.

Criminals don’t have to kidnap anyone to engage in extortion these days. The ubiquitous connectivity via worldwide web has allowed such a felony to go digital. As a result, thousands of computer users around the world are catching malicious code every single day, the type thereof that utilizes cryptography to render data inaccessible in the blink of an eye. Because the recovery is a matter of having the decryption key in this scenario, the crooks who keep this secret chunk of data are in a position of strength and demand money – usually cryptocurrency – for reinstating the seemingly lost files.

The authors of the GandCrab ransomware, one of the dominating lineages at this point, aren’t reinventing the wheel whatsoever and are sticking with this well-trodden path that’s common for pretty much any other blackmail malware family out there. However, this infection, including its latest variant GandCrab 5.0.4, still stands out from the majority in a few ways.

GandCrab 5.0.4 ransomware attack in full swing
GandCrab 5.0.4 ransomware attack in full swing

Contrary to many other ransom Trojans across the board, GandCrab v5.0.4 extends the visual threat effect by changing the desktop wallpaper on a contaminated host. It simply replaces the one preferred by the victim with a dark-colored image with some recovery guidance text on it. This tactic makes the attack appear scarier and coerces many victims to hurry with their ransom payment. Also, this iteration employs a fusion of different spreading mechanisms. It can reach hosts by means of malicious spam, RDP brute-force attacks, bad code lurking on compromised websites, and exploit kits that take advantage of unpatched software vulnerabilities.

Once the attack has taken place, the victim faces a number of obvious outcomes. In addition to the above-mentioned desktop wallpaper getting skewed by the baddie, GandCrab 5.0.4 locks down the victim’s personal files and appends a random extension of arbitrary length to each one. The suffix can be up to 9 characters long and, while it doesn’t seem to make any sense or follow any apparent logic, it is unique for every victim, and that does the trick for the crooks as they can identify the infected users this way. As a result, a sample entry named 1.pdf will turn into 1.pdf.lwgapmlcu or something similarly gibberish.

[random]-DECRYPT.txt ransom note covering decryption steps as viewed by the attacker
[random]-DECRYPT.txt ransom note covering decryption steps as viewed by the attacker

The inalienable attribute of a ransomware attack – and GandCrab 5.0.4 is no exception – is a ransom note, or a series of them. In this case, victims are instructed to peek into a file named [random string]-DECRYPT.txt, where the segment in brackets is the same as the newly assigned file extension, except that the characters are uppercase. Essentially, this document is a manual that lists steps to get started on the data recovery process, in case the victim is okay with the ransom in the first place. It urges the infected user to install Tor browser and follow their personal link via this privacy-centered Internet navigation tool. What this link leads to is the payment page that says how much to pay and whom to pay. The amount is typically somewhere around 800 USD worth of Bitcoin or DASH. Well, that’s basically it for the conspicuous part of the pest’s activity. That’s only the tip of the iceberg, though.

GandCrab 5.0.4 appears to feature an overhauled cryptographic implementation. This might be the wicked developers’ response to the recent release of the free decryptor by Bitdefender Labs. According to victims’ reports, the decryption tool doesn’t support v5.0.4, although it works wonders for sub-editions of the culprit’s fifth generation up to version 5.0.3. Furthermore, a really bizarre thing about GandCrab 5.0.4 is that it may sprinkle images of a particular person all over the plagued system. Those are photos of someone named Valery Sinyaev, who turns out to be a finance executive at a Russian logistics firm. The ransomware creators probably hold a grudge against that individual, whatever.

GandCrab v5.0.4 is still a severe threat, and the crooks have made some coding and cryptographic tweaks to prevent easy recovery. Although the infection is programmed to delete volume shadow copies of a user’s files, it attempts to do it at the very end of the attack chain, which isn’t really the commonplace approach. This may leave some small chance of failure in disabling the VSS. Anyway, such a vector of data restoration is worth trying. All the applicable recovery methods, including this one, are described below in detail.

GandCrab 5.0.4 ransomware automated removal and data recovery

When faced with ransomware like GandCrab 5.0.4, 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 5.0.4 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.

Download and run Combo Cleaner installer on your PC

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.Setup customizations

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.Start initial scan

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.Combo Cleaner scan in progress

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.Scan completed

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.Scan results

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.Stellar Data Recovery main screen

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

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.Recover files

GandCrab 5.0.4 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 5.0.4 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.

Remove GandCrab 5.0.4 ransomware using Safe Mode with Networking

Remove GandCrab 5.0.4 ransomware using Safe Mode with Networking

Get rid of GandCrab 5.0.4 ransomware using System Restore

Get rid of GandCrab 5.0.4 ransomware using System Restore

System Restore enables Windows users to roll back all changes made to the OS since the latest restore point creation time. This feature can help eliminate the most persistent ransomware. Before going this route, though, make sure System Restore had been enabled prior to the breach, otherwise the method will be inefficient.

  • Open Windows Advanced Options Menu as described in the previous section: hit F8 repeatedly when the PC is starting up. Use arrow keys to highlight the Safe Mode with Command Prompt entry. Hit Enter.Safe Mode with Command Prompt
  • In the Command Prompt window, type cd restore and hit Entercd restore command
  • Type rstrui.exe in the new command line and press EnterType rstrui.exe command
  • When the System Restore screen pops up, click Next, select a restore point that predates the contamination, and use the application’s controls to roll back the system to this earlier state.System Restore window
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 5.0.4

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.

Backups can make your day

Backups can make your day

Not only are you a lucky person in case you’ve been backing up your most important files, but you’re also a wise and prudent user. This isn’t necessarily a resource-heavy activity these days – in fact, some providers of online services are allocating a sufficient size of cloud storage space for free so that every customer can easily upload their critical data without paying a penny. Having removed the GandCrab 5.0.4 ransomware, therefore, all you have to do is download your stuff from the remote server or transfer it all from an external piece of hardware if that’s the case.

Restore previous versions of encrypted files

Restore previous versions of encrypted files

A positive upshot of using this technique depends on whether or not the ransomware has erased the Volume Shadow Copies of the files on your PC. This is a Windows feature that automatically makes and keeps the backups of data elements on the hard drive as long as System Restore is enabled. The cryptoware in question is programmed to switch off the Volume Shadow Copy Service (VSS), but it has reportedly failed to in some cases.

Checking one’s options regarding this workaround is doable in two ways: through the Properties menu of each file or by means of the remarkable open-source tool called Shadow Explorer. We recommend the software-based way because it’s automated, hence faster and easier. Just install the app and use its intuitive controls to get previous versions of the encrypted objects reinstated.

Shadow Explorer

Alternatively, you can leverage the Previous Versions feature, which is native to Windows operating system. This method is more cumbersome that the use of ShadowExplorer, but it can help restore the most important individual files on condition that the ransomware failed to disable the Volume Snapshot Service on the computer. Right-click on a file of choice and select Properties. Then, go to the Previous Versions tab as illustrated below.

Previous Versions

Go ahead and pick the file’s latest backup version on the list. Use the Copy or Restore buttons to reinstate this object to a new path or to its original folder, respectively.

Ransomware Prevention Tips

To avoid GandCrab 5.0.4 ransomware and other file-encrypting infections in the future, follow several simple recommendations:

  • Toggle your email provider’s anti-spam settings to filter out all the potentially harmful incoming messages. Raising the bar beyond the default protection is an important countermeasure for ransom Trojans
  • Define specific file extension restrictions in your email system. Make sure that attachments with the following extensions are blacklisted: .js, .vbs, .docm, .hta, .exe, .cmd, .scr, and .bat. Also, treat ZIP archives in received messages with extreme caution
  • Rename the vssadmin.exe process so that ransomware is unable to obliterate all Shadow Volume Copies of your files in one shot
  • Keep your Firewall active at all times. It can prevent crypto ransomware from communicating with its C&C server. This way, the threat won’t be able to obtain cryptographic keys and lock your files
  • Back up your files regularly, at least the most important ones. This recommendation is self-explanatory. A ransomware attack isn’t an issue as long as you keep unaffected copies of your data in a safe place
  • Use an effective antimalware suite. There are security tools that identify ransomware-specific behavior and block the infection before it can do any harm.

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 5.0.4 removal tool

One Comment

  1. Amr Helmy

    December 8, 2018 at 6:15 pm

    On November 2018, I discovered that my PC was affected by GANDCRAB V5.0.4 by referring to HRMGI. It seems to be everywhere in my computer. I have downloaded Bitdefender GandCrab V1, V4, V5 .
    I have also followed the steps properly. Each time I try to scan using Bitdefender GandCrab V1, V4, V5 Decryptor – system looking for encryption key. After a while, it is shown that initialization failed.


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