RZKD Virus (.RZKD File) 🔐 Decrypt & Removal Guide

The Rzkd virus, also known as a ransomware, belongs to the STOP family. This malware is notorious for malicious file ciphering. When the Rzkd malware gets into a computer system, it targets various types of files, such as photos, videos, documents, and more. It changes the file structure and adds the “.rzkd” extension to each encrypted file, making them inaccessible and unusable without the decryption key.

Rzkd Virus Overview

Rzkd

🤔 Rzkd malware is ransomware that belongs to the DJVU/STOP ransomware family. Its primary purpose is to cipher all of your files it can reach. Then, ransomware asks its victims for a ransom fee – ($490 – $980) in Bitcoin.

Rzkd ransomware aims at encrypting your files and forcing you to pay for the decryptor tool. This malware encrypts different file types, mostly videos, photos, Photoshop projects, archives etc. Files encrypted by Rzkd virus can be identified by a distinct “.rzkd” extension. You will not be able to either access or use these files in a regular way.

Once the encryption process is over, ransomware begins asking the payment for files decryption. It generates a text file with ransom payment guidances is named as “_readme.txt” in every folder with encrypted files. The note contains instructions on how to pay in Bitcoin and the sum progression information – $490 during the first 72 hours, then it boosts to $980.

Rzkd Ransomware operates by Salsa20 encryption algorithms to scramble the contents of the targeted files. Since Rzkd malware uses such a strong ciphering method, it becomes really hard, if even possible, to pick the decryption key without cooperating with the attackers.

Once the files are encrypted, the Rzkd virus displays a ransom note to the user, asking for a ransom payment for the decryption key. The ransom note provides instructions on how to pay off the bill and often contains threats of data loss or increased ransom amounts if the ransom is not paid within a specified timeframe.

I have created an all-encompassing list of potential solutions, advice, and approaches to disable the Rzkd ransomware and recover access to your files. In some cases, you can regain access to the files, while sometimes, it may be impossible.

Subscribe to our Telegram channel to be the first to know about news and our exclusive materials on information security.

📌 Important Reminder!

It is essential to voice that paying off the ransom does not guarantee the successful recovery of your files. The rascals behind the Rzkd virus are not trustworthy. There were the cases where victims have paid the ransom, only to be denied by the cybercriminals with the decryption key provision.

Rzkd employs a unique key for every victim, with one exception:

The Rzkd virus is highly similar to other DJVU ransomware samples like Teza, Nzqw, Nzer, and Nzoq. This virus encrypts a wide range of common file types and appends its distinct “.rzkd” extension to all files. For instance, a file named “1.jpg” would be altered to “1.jpg.rzkd” and “2.png” to “2.png.rzkd“.

After successful encryption, malware creates a special text file named “_readme.txt” and places it in every folder containing the encrypted files. It as well adds the readme file to the desktop, so the user will not miss the attack even without opening folders.

The image below provides a visual representation of files with the “rzkd” extension:

Encrypted Files by STOP/DJVU Ransomware

Name	Rzkd Virus
Ransomware family¹	DJVU/STOP² ransomware
Extension	.rzkd
Ransomware note	_readme.txt
Ransom	From $490 to $980 (in Bitcoins)
Contact	[email protected], [email protected]
Detection	Spyware:Win32/Stealc, Trojan:Win32/Gepys.A!MTB, Win32:Monder-V [Trj]
Symptoms	Installs password-stealing Trojan on the system, like Vidar Stealer or RedLine Stealer; Adds a list of domains to HOSTS file to block access to certain security-related sites; Encrypts most of your files (photos, videos, documents) and adds a particular “.rzkd” extension; Manages to install a SmokeLoader backdoor; Can delete Volume Shadow copies to make victim’s attempts to restore data impossible;
Fix Tool	To remove possible malware infections, scan your PC: 6-day free trial available.

This message asking payment is for restore files via decryption key:

_readme.txt (STOP/DJVU Ransomware) – The scary warning demanding users to pay the ransom to unlock the encrypted data contains these exasperating warnings.

Rzkd ransomware arrives as a set of tasks that are needed to carry out certain tasks on a victim’s computer. One of the primary ones being launched is winupdate.exe, a sneaky process that shows a false Windows update prompt during the attack. Such a trick helps to convince the victim that a sudden PC slowdown is caused by a Windows update.

Meanwhile, the ransomware runs another process (named as 4 random chars) which commences scanning the computer for target files and encrypting them. Next, the ransomware removes Volume Shadow Copies from the disk through the following CMD command:

vssadmin.exe Delete Shadows /All /Quiet

Once erased, it becomes impossible to restore the previous computer state using System Restore Points. The problem is, ransomware operators are eliminating any built-in Windows approaches that could aid the victim to restore files for free. In addition, the crooks modify the Windows HOSTS file by adding a list of domains to it and linking them to the localhost IP. As a result, the victim will witness a DNS_PROBE_FINISHED_NXDOMAIN error when trying to open one of the blacklisted websites.

We noticed that ransomware endeavors to restrict websites that promote various how-to guides for computer users. It is clear that by hindering specific domains, the perpetrators are attempting to stop the victim from reaching relevant and helpful ransomware-attack-related information online. Malware also keeps two .txt files on the victim’s computer that present attack-related details – the victim’s public encryption key and personal ID. These two files are named bowsakkdestx.txt and PersonalID.txt.

After all these changes, the malware doesn’t halt. Variants of STOP/DJVU have a tendency to deploy Vidar password-stealing Trojan on compromised systems. This threat carries an large list of capabilities, including:

Stealing Steam, Telegram, Skype login / password;
Stealing cryptocurrency wallets;
Downloading other malware to the computer and running it;
Stealing browser cookies, saved passwords, browsing history, and more;
Viewing and manipulating files on victim’s computer;
Allowing the hackers to perform other tasks on the victim’s computer remotely.

The cryptography algorithm in STOP/Djvu ransomware is AES-256. So, once your data is encrypted with an online decryption key, the possibility to get your files back without paying the ransom are quite low. Thing is, this key is unique for each victim, and picking it will take exceptionally big amount of time.

Obtaining the online key in another way is also merely impossible. It is stored on a remote server controlled by the hackers who spread the Rzkd infection. For receiving decryption key the payment should be $980. To see the payment details, the victims should contact the hackers by email ([email protected]).

The message by the ransomware states the following information:

ATTENTION!

Don't worry, you can return all your files!

All your files like photos, databases, documents and other important are encrypted with strongest encryption and unique key.
The only method of recovering files is to purchase decrypt tool and unique key for you.
This software will decrypt all your encrypted files.

What guarantees you have?

You can send one of your encrypted file from your PC and we decrypt it for free.
But we can decrypt only 1 file for free. File must not contain valuable information.

You can get and look video overview decrypt tool:

https://we.tl/t-WJa63R98Ku

Price of private key and decrypt software is $980.
Discount 50% available if you contact us first 72 hours, that's price for you is $490.

Please note that you'll never restore your data without payment.

Check your e-mail "Spam" or "Junk" folder if you don't get answer more than 6 hours.

To get this software you need write on our e-mail:

[email protected]

Reserve e-mail address to contact us:

[email protected]

Your personal ID:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Do not pay the ransom!

Please, try to use the available backups, or Decrypter tool

The _readme.txt document also requests that the system owner must get in touch with the hackers’ representatives during 72 hours after the attack. If user contacts hackers during 72 hours, hackers grant a 50% discount. This decreases the ransom sum down to $490.

Yet, stay away from paying off the ransom! I highly recommend that you do not contact these fraudsters and do not pay. One of the most real working solution to recover the lost data is just using the backups you have, or using Decrypter tool from Emsisoft.

The distinctiveness of such malware is the employment a similar set of actions for generating the unique decryption key to recover the ciphered data. Thus, unless the ransomware is still under the stage of development or has some hard-to-track flaws, manually recovering the ciphered data is a thing you can’t perform. The only solution to prevent the data loss is to regularly make backups of your important files.

Note that even if you do maintain such backups regularly, they ought to be located into a specific location without loitering, not being connected to your main workstation. For instance, the backup may be kept on the USB flash drive or some optional external hard drive storage. Alternatively, you may turn to the help of online (cloud) information storage.

It goes without saying, when you keep your backup data on your common device, it may be encrypted together with your files. For this reason, placing the backup on your computer’s disk is surely not a wise idea.

How I was infected?

Ransomware has a various methods to built into your system. But it doesn’t really matter what way had place in your case.

Ransomware attack following a successful phishing attempt.

Nevertheless, these are the common leaks through which it may be injected into your PC:

Concealing the virus within seemingly legitimate apps, especially utilities provided as freeware or shareware.
Spreading the virus through spam emails containing suspicious links that lead to the virus installer.
Exploiting online free hosting resources to host and distribute the virus files discreetly.
Obtaining pirated software from illegal peer-to-peer (P2P) resources, which may unknowingly contain malware.

There were cases when the Rzkd virus hiding as a legit thing, for example, the messages insisting to start a browser update or a vastly needed codec for online media playback. This is typically the way how some online frauds aim to force you into installing the ransomware manually, by actually making you directly involve in this process.

Surely, the fraudulent update alert will not indicate that you are installing the threat. This process will be disguised under some alert stating that you must install an urgent security update or some suspicious program whatsoever.

Of course, the software cracks represent the threat as well. Using P2P is both illegal and may result in the injection of serious malware, including the Rzkd ransomware.

To sum up, what can you do to prevent the injection of the ransomware into your computer? Even though there is no 100% guarantee to prevent your PC from getting infected, there are certain tips I want to give you to avert the Rzkd penetration. You must be careful while installing free software today.

Verify you always read what the installer offers aside from the main free program. Keep away from running dubious email attachments. Do not run files from the unknown addressees. Of course, your current security program must always be updated.

The malware does not states openly about itself. It will not be mentioned in the list of your available programs. Instead, it will be masked under some malevolent process running consistently in the background, that starts at the moment when you launch your computer.

How To Remove Ransomware?

Video Guide

How To Decrypt .rzkd Files?

How to restore big files?

Try deleting .rzkd extension on a few big files and opening them. This malware has issues with large files encryption. Either the virus read and did not lock the file, or it failed and did not add the filemarker. If your files are very large (2GB+), the latter is most likely. Please, text me in the comments whether this helped you or not.

The newest extensions released around the end of August 2019 after the criminals made changes. This includes Teza, Nzqw, Nzer etc.

As a result of the changes made by the criminals, STOPDecrypter is no longer supported. It has been replaced with the Emsisoft Decryptor for STOP Djvu Ransomware developed by Emsisoft.

You can download free decryption tool here: Decryptor for STOP Djvu.

Select folders for decryption.

Based on the default configurations, the decryptor will automatically choose the accessible directories in order to decode the currently reachable drives (the connected ones), including the network drives. Additional (optional) locations can be selected with the aid of the “Add” button.

Decryptors typically offer several options depending on the specific malware family. The present possible options are shown in the Options tab and can be turned on or disabled there. You may find a detailed list of the currently active Options below.

Click on the “Decrypt” button.

As soon as you add all the desired locations for decryption into the list, click on the “Decrypt” button in order to initiate the decryption procedure.

Note that the main screen may turn you to a status view, letting you know of the active process and the decryption statistics of your data:

The decryptor will notify you as soon as the decryption procedure is completed. If you need the report for your personal papers, you can save it by choosing the “Save log” button. Note that it is also possible to copy it directly to your clipboard and to paste it into emails or messages here if you need to do so.

The Emsisoft Decryptor might display different messages after a failed attempt to restore your files:

✓ Error: Unable to decrypt file with ID: [your ID]

Emsisoft failed to find a correspondnig decryption key in their database.

✓ No key for New Variant online ID: [your ID]

Notice: this ID appears to be an online ID, decryption is impossible

Malware used an online key to cipher your files. Your key is unique and is kept on the command server, controlled by criminals. File recovery without paying the ransom is impossible. 🙁

✓ Result: No key for new variant offline ID: [example ID]

This ID appears be an offline ID. Decryption may be possible in the future.

An offline key was used, but files could not be restored (the offline decryption key isn’t available yet). Nonetheless, receiving this message is good news for you, because it is possible to restore your files in the future. 🙂
It can take a few weeks or months until the decryption key gets found and uploaded to the decryptor. Please follow updates regarding the decryptable DJVU versions here.

✓ Remote name could not be resolved

This stands for a DNS issue present in your system. Consider resetting your HOSTS file to default.

How to Restore .rzkd Files?

In some case ransomware is not doom for your files…

The Rzkd ransomware encryption mechanism feature is next: it encodes every file byte-by-byte, then saves a duplicate, removing (not overriding!) the initial file. Hence, the information of the file placement on the disk drive is lost, but the original file is not erased from the disk. The cell, or the sector where this file was kept, can still keep this file, but it is absent in the file system and can be rewritten by data that has been loaded to this drive after the deletion. Hence, it is possible to recover your files using special software.

I recently had my pc infected by the this virus. It managed to bypass 2 Antivirus software and 2 malware fighters.

Anyway, after realizing it was an online algorithm, it is impossible to retrieve my encrypted files. I also had my backup drive plugged in at the time of the virus, and this was also infected, or so I thought. Every folder within my backup drive had been infected and was encrypted. However, despite losing some important files, I retrieved almost 80% of my 2TB storage.

When I started going through the folders, I noticed the readme.txt ransom note in every folder. I opened some of the folders and found that all files that were not in a subfolder within that folder had been encrypted. However, I found a flaw and glimmer of hope when I went into the subfolders in other folders and found that these files had not been encrypted. Every folder within my c and d drives, including subfolders, had been encrypted, but this was not the case with the backup drive. Having subfolders created within a folder has saved 80% of my data.

As I said, I believe this to be only a small loophole on a backup drive. I’ve since found a further 10 % of my data on another hard drive on a different pc. So my advice is if you use a backup drive, create subfolders. I was lucky, I guess. But I was also unlucky that the virus hit as I was transferring some files from my backup.

Hopefully, this can help some other people in my situation.

Jamie Newland

Some pointers for recovery repair of Rzkd files (true for all STOP/DJVU variants):

I have seen Stop/Djvu variants fail to encrypt deeper nested folders, so that you can check that. You may find those are not encrypted.

This ransomware saves encrypted data to a new file, deletes the original. So there’s a slight chance part of that deleted file can be recovered using file recovery software. It’s unlikely the folder structure can be restored, so a free tool like PhotoRec may be as good as any.

This ransomware only partially encrypts (about the first 150 KB), so depending on file size and type of data, the not encrypted part may be recoverable.

Joep

Recovering your files with PhotoRec

PhotoRec is an open-source program, which is originally created for file retrieval from damaged disks, or for data recovery in case if they are unintentionally deleted. However, with time flow, this program adopted the ability to restore the files of 400 different formats. Hence, it can be used for file restoration after the Rzkd attack.

First, you need to download this app. It is 100% free, but the developer notifies that there is no assurance that the files will be recovered. PhotoRec is spread in a pack with another utility of the same developer – TestDisk. The resulting archive will bear TestDisk name, but don’t worry. PhotoRec files are right inside.

To open PhotoRec, find and open “qphotorec_win.exe” file. No installation is required – this program has all the files it need inside of the archive, hence, you can fit it on your USB drive, and help your friends/parents/anyone who has been attacked by Rzkd ransomware.

Upon the launch, you will observe the screen showing you the complete list of your disk spaces. However, this data is likely unhelpful, because the required menu is placed a bit higher. Click this tab, then choose the disk which was attacked by ransomware.

After opting for the disk, you need to select the destination folder for the restored files. This menu is located at the lower part of the PhotoRec window. The best selection is to export them on USB drive or any other type of removable disk.

Then, you need to indicate the file formats. This choice is located at the bottom, too. As it was mentioned, PhotoRec can retrieve the files of about 400 different formats.

Finally, you can start files recovery by pressing the “Search” button. You will observe the screen where the results of the scan and recovery are shown.

Rzkd files recovery Video Guide.

Frequently Asked Questions

🤔 How can I open “.rzkd” files?

No way. These files are encrypted by ransomware. The contents of encrypted files are not available until they are decrypted.

🤔 Encrypted files contain important information. How can I decrypt them urgently?

If your data remained in the .rzkd files are very valuable, then most likely you made a backup copy. If not, then you can try to restore them through the system function – Restore Point. All other methods will require patience.

🤔 You have advised using GridinSoft Anti-Malware to remove Rzkd. Does this mean that the program will delete my encrypted files?

Of course not. Your encrypted files do not pose a threat to the computer. What happened has already happened.

🤔 This virus has blocked infected PC: I can’t get the activation code.

In this situation, you need to prepare the memory stick with a pre-installed

🤔 Decryptor did not decrypt all my files, or not all of them were decrypted. What should I do?

Have patience. You are infected with the new version of STOP/DJVU ransomware, and decryption keys have not yet been released. Follow the news on our website. We will keep you posted on when new keys or new decryption programs appear.

🤔 What can I do right now?

The Rzkd ransomware encrypts only the first 150KB of files. So MP3 files are rather large, some media players (Winamp for example) may be able to play the files, but – the first 3-5 seconds (the encrypted portion) will be missing. You can try to find a copy of an original file that was encrypted: Files you downloaded from the Internet that were encrypted and you can download again to get the original.