Remove Ryuk ransomware (Virus Removal Instructions) - Free Guide

removal by Jake Doevan - - | Type: Ransomware

Ryuk virus Removal Guide

What is Ryuk ransomware?

Ryuk ransomware is large-scale malware that chooses its targets carefully

Ryuk RansomwareRyuk ransomware is a crypto virus that locks your data to demand payment.

Ryuk is a ransomware virus[1] that, since August 2018, has already attacked and encrypted data from several companies, data centers, and PC users. According to numerous claims, the virus stems from the same family as Hermes ransomware which is attributed by an infamous Lazarus group. It shocked cybersecurity experts after they found out that the malware can misuse the Wake-on-Lan feature to turn the computer on and increase the number of infected devices on the network. It has a copy of Hermes cryptovirus coding and the Bitpaymer ransomware-resembling text in the ransom note but none of these relations were confirmed as genealogy features by researchers.

After Ryuk ransomware encrypts systematically selected data, it generates a RyukReadMe.txt ransom note with the ransom fee that varies from 15 BTC to 50 BTC, depending on the amount of encrypted data via the provided Bitcoin wallet.[2] Ransomware returned to the headlines after performing several attacks during the Christmas time, including the cloud hosting provider.[3] This new version has been named RYK ransomware due to the file extension appended. However, note that alternatively it has been called a Cryptor2.0.

Ransom payments averaged around $10,000 in 2018, but Ryuk ransomware made this average come up to $111,605 for the first quarter of 2020 especially due to the fact that this virus is used in 19,6 percent of all ransomware attacks. Even though researchers noticed a slight decrease in attacks involving this malware strain. It is still used against large organizations with at least 1,000 workers. Developers ask for $1,4 million from each victim on average so it becomes the most profitable ransomware of recent years.

Name Ryuk
Also known as Cryptor 2.0, RYK ransomware
Category Ransomware/cryptovirus/malware
estimated income Around $3.7 million
Encryption algorithms AES-256; RSA-4096
Ransom notes RyukReadMe.txt, UNIQUE_ID_DO_NOT_REMOVE.txt, ReadMe.txt, RyukReadMe.html
Ransom amount 15 – 50 BTC. A recent analysis showed that the average amount asked from Ryuk victims is $1,4 million
Related files horrible.exe, kIUAm.exe
Email addresses used for contacting
Blocked services Acronis VSS Provider, Sophos-related services, Veeam backup service, MBAM service, McAfeeEngine service, etc.
Elimination Download anti-malware and run a full system scan. After Ryuk ransomware removal, follow the guide on how to decrypt encrypted files (at the end of the post)

According to the latest news reports, Ryuk ransomware is still rapidly spreading throughout the Internet sphere and infecting users worldwide. The Federal Bureau of Investigation, also known as FBI, has made a research and found out that this cyber threat has launched dangerous attacks on more than 100 different types of businesses in The United States of America.[4]

Additionally, all of this took place starting from August 2018 until the middle of May 2019. This is a very big number of infected companies throughout such a period of time. Experts think that the reason why Ryuk ransomware has been so successful is that it also delivers other destructive viruses such as TrickBot and Emotet. The variety of suffered organizations is wide, such as logistics companies, technology-based manufactures, and similar.

Researchers are still working on getting more knowledge about this ransomware distribution means. However, it has been speculated that it is distributed in the form of a phishing email attachment which typically presents itself as an invoice, business report, etc. Additionally, hackers are likely to abuse insufficiently protected RDP[5] configurations to attack targeted companies.

To run on the computer, Ryuk malware needs to gain admin privileges. Therefore, each of the attacks needs to be carefully planned, credentials gathered, network mapped, etc. This led researchers from Check Point to believe[6] that the infection is carefully engineered by sophisticated hackers who are experienced in targeted attacks. According to Check Point experts, the malware has extreme similarities to Hermes 2.1 ransomware which belongs to the infamous Lazarus group who were formerly associated with the North Korean army.

crypto virusRansomware tends to attack both - regular users and high-profile organizations

The latest virus version, Cryptor2.0, hits Data Resolution and Tribune Publishing

After staying still for some time, the new version of Ryuk ransomware hit again during the Holiday 2018. Experts encountered the rise of its activity on December 24 and December 27. The first campaign was held on Data Resolution when ransomware gave control of the important data to the attacker. The data center domain was accessible until the company shut down the whole network. According to Data Resolution, no user data was accessed or compromised. The main purpose of this ransomware was to hijack the network not to steal the credentials.

On December 27, 2018, Ryuk hit Tribune Publishing newsprint organizations and disabled their ability to print papers. The incident was discovered late at night when one editor could not send finished pages to the printing service. The issue was quickly fixed and no more damage discovered on the network.

It is obvious that Ryuk ransomware is still active. According to the latest reports, both Data Resolution and Tribune Publishing were affected by Cryptor2.0 which is considered to be the newest variant of the Ryuk virus. Once installed, this cyber threat encrypts files and marks them with the .RYK appendix. Additionally, it displays a ransom note explaining all conditions needed to get the decryption tool.

According to the note, victims are given a chance to recover two files for free, however, for the other ones, the users need to be a particular price. All details need to be discussed by email. Moreover, the criminals hiding behind virus threaten users not to reset, shut down the computer, or delete any files because all data will be permanently deleted. Another version of RyukCryptor 2.0 - another version of Ryuk ransomware virus

The functionality of the malware

Before infecting the device, Ryuk ransomware shuts down 180 services and more than 40 processes that are running on the system. The malware executes taskkill and net stop command on a predetermined list of processes and services.

The Ryuk virus then uses the kIUAm.exe executable file which is launched once the victim reboots the system. Right after that, it encrypts victim’s data, e.g., business documents, reports, photos, videos, databases, and other personal information with the specific file extension using the combination of RSA-4096 and AES-256 encryption algorithms.

Upon successful encryption, the virus generates ransom notes named RyukReadMe.txt and UNIQUE_ID_DO_NOT_REMOVE.txt. They read the following:

All files on each host in the network have been encrypted with a strong algorithm.
Backups were either encrypted or deleted or backup disks were formatted.
Shadow copies also removed, so F8 or any other methods may damage encrypted data but not recover.
We exclusively have decryption software for your situation
No decryption software is available in the public.
DO NOT RESET OR SHUTDOWN – files may be damaged.
DO NOT RENAME OR MOVE the encrypted and readme files.
DO NOT DELETE readme files.
This may lead to the impossibility of recovery of the certain files.
To get info (decrypt your files) contact us at
BTC wallet:
No system is safe

If the virus attacks a company or similar authority, it drops such note:

Your business is at serious risk.
There is a significant hole in the security system of your company.
We’ve easily penetrated your network.
You should thank the Lord for being hacked by serious people not some stupid schoolboys or dangerous punks.
They can damage all your important data just for fun.
Now your files are crypted with the strongest millitary algorithms RSA4096 and AES-256.
No one can help you to restore files without our special decoder.
Photorec, RannohDecryptor etc. repair tools are useless and can destroy your files irreversibly.
If you want to restore your files write to emails (contacts are at the bottom of the sheet) and attach 2-3 encrypted files
(Less than 5 Mb each, non-archived and your files should not contain valuable information
(Databases, backups, large excel sheets, etc.)).
You will receive decrypted samples and our conditions how to get the decoder.
Please don’t forget to write the name of your company in the subject of your e-mail.
You have to pay for decryption in Bitcoins.
The final price depends on how fast you write to us.
Every day of delay will cost you additional +0.5 BTC
Nothing personal just business
As soon as we get bitcoins you’ll get all your decrypted data back.
Moreover you will get instructions how to close the hole in security and how to avoid such problems in the future
+ we will recommend you special software that makes the most problems to hackers.
Attention! One more time !
Do not rename encrypted files.
Do not try to decrypt your data using third party software.
P.S. Remember, we are not scammers.
We don’t need your files and your information.
But after 2 weeks all your files and keys will be deleted automatically.
Just send a request immediately after infection.
All data will be restored absolutely.
Your warranty – decrypted samples.
contact emails
BTC wallet:
No system is safe

While Ryuk ransomware removal will not give users access to the files, it will get rid of the infection itself. We strongly recommend using reputable security software like ReimageIntego or SpyHunter 5Combo Cleaner which is capable of destroying all the traces of malware.

Ryuk ransomware virusRyuk ransomware is an infamous computer virus which appears to have relation with Hermes

While hackers are actively trying to convince victims that paying the ransom is a great idea (they even go as far claiming that they will reveal the security hole and show how to fix it), security researchers[7] advise not to. These people are from a high-profile crime organization and can not be trusted. Additionally, despite criminals' warnings, you should remove Ryuk ransomware as soon as possible.

Ryuk ransomware actors are back after a break

Cybercriminals behind ransomware are usually keeping their attacks consistent, and new victims emerge on a regular basis. However, taking breaks is also not unusual for one reason or another – the Ryuk gang seemed to be doing just that for a long time until a new campaign was spotted in September 2020.

Security researchers at Sophos detailed this new campaign in their security research report, claiming that actors are now back and claiming victims one after the other. The new campaign revolves around sending out targeted phishing emails – it serves as the main attack vector. Experts also claim that the criminal gang has improved and evolved their tools, techniques, and practices.[8]

To begin the attack, Ryuk ransomware actors deployed an array of highly-targeted phishing emails directed to the company's employees. One of the emails read:

From: Alex Collins [spoofed external email address]

To: [targeted individual]

Subject: Re: [target surname] about debit

Please call me back till 2 PM, i will be in [company name] office till 2 PM.

[Target surname], because of [company name]head office request #96-9/23 [linked to remote file], i will process additional 3,582 from your payroll account.

[Target first name], call me back when you will be available to confirm that all is correct.

Here is a copy of your statement in PDF[linked to remote file].

Alex Collins

[Company name] outsource specialist

As soon as the alleged PDF is opened, it redirects users to a Google Doc file, which, once opened, executes a “print_document.exe.” This file is malware loader (known as Buer Loader malware-as-a-service being sold for $350 on the underground forums) – it contacts a remote server and downloads the malicious payload on the target system.

Malicious actors managed to break into domain controllers and obtain critical information needed to proceed with the attack. Just within four hours after the malicious file was launched, several servers were compromised. Within a day, actors attempted to launch the Ryuk ransomware on the targeted network, although this attempt failed – only ransom notes were dropped on the compromised server, and no data encrypted.

Ryuk ransomware gang is backRyuk ransomware gang is back with new techniques

Researchers said that the malware itself did not differ much from its previous versions. However, they noted that hackers added additional obfuscation measures to prevent security tools from detecting payload within the system's memory.

Without a doubt, this attack proves that the Ryuk virus gang is not going anywhere, and it is ready to employ several break-in tools in order to achieve what they came for – ransom demands.

New variant of Ryuk takes care that matching PCs could not be encrypted

A new version of Ryuk ransomware has been first spotted by experts from MalwareHunterTeam.[9] This variant of the ransomware operates by using a newly-discovered technique. Once inserted on the computer, the malware will start searching for IP strings such as 10.30.4, 10.30.5, 10.30.6, and 10.31.32.

If these IPs are found by Ryuk on the targeted computer system, the virus does not perform any encryption on stored files and documents. Nevertheless, this file-locking threat detects the computer name and searches for strings such as “MSK”, “Msk”, “msk”, “SPB”, “Spb”, and “spb”.

If these two components match, Ryuk ransomware will not encrypt the computer also. According to the opinions of cybersecurity researchers, hackers use such techniques to prevent encryption of computer systems which are based in Russia. However, such a technique might not seem quite successful if worming activities are performed.

Distribution techniques evolve from spam email to trojan malware

According to PC experts, the virus is using phishing email messages to get into the target PC systems. Usually, a large amount of these messages is sent to businesses to increase the number of encrypted files and earn bigger ransoms. Beware that you need only to click on an infected email attachment to get infected with ransomware. Such messages can also be filled with trustworthy-looking logos, addresses, and similar information pretending to be from Lloyds Bank, HSBC, and similar companies that could increase chances to infect the victim with the ransomware virus.

To avoid the loss of important data, you need to be extremely careful with emails from unknown senders. Make sure you doublecheck every line included and use your mouse to check the trustworthiness of links you have been sent to.

There is a theory that Emotet and TrickBot are used to distribute this ransomware. After gaining the connection to the target network, these viruses bring additional malware to the system in exchange for a certain fee. Often, the Trickbot has been rented only to certain people.

Make sure to remove Ryuk ransomware from the system using professional tools

To perform Ryuk removal, make sure you do not consider using manual removal techniques. This is a serious virus that travels around with numerous components that can be found only by running a full system scan with anti-spyware. In this case, we recommend using SpyHunter 5Combo Cleaner or Malwarebytes which have been approved to be powerful enough to fight against such complicated malware. Additionally, check the system with ReimageIntego for altered registry entries and similar components (does not encrypt files).

Unfortunately, once you remove Ryuk ransomware from the system, your files will still be encrypted. That's because the decryption key needed to recover locked data is saved on the remote servers that belong to the crew of this ransomware. However, don't be desperate and think whether you have extra copies of your encrypted data saved on external devices. If no, use tips provided below to decrypt files encrypted by Ryuk.

do it now!
Reimage Happiness
Intego Happiness
Compatible with Microsoft Windows Compatible with macOS
What to do if failed?
If you failed to remove virus damage using Reimage Intego, submit a question to our support team and provide as much details as possible.
Reimage Intego has a free limited scanner. Reimage Intego offers more through scan when you purchase its full version. When free scanner detects issues, you can fix them using free manual repairs or you can decide to purchase the full version in order to fix them automatically.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Reimage, try running SpyHunter 5.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Intego, try running Combo Cleaner.

Getting rid of Ryuk virus. Follow these steps

Manual removal using Safe Mode

To delete Ryuk ransomware with Safe Mode, you need to perform this procedure on your computer. Repeat the scan when on normal mode.

Important! →
Manual removal guide might be too complicated for regular computer users. It requires advanced IT knowledge to be performed correctly (if vital system files are removed or damaged, it might result in full Windows compromise), and it also might take hours to complete. Therefore, we highly advise using the automatic method provided above instead.

Step 1. Access Safe Mode with Networking

Manual malware removal should be best performed in the Safe Mode environment. 

Windows 7 / Vista / XP
  1. Click Start > Shutdown > Restart > OK.
  2. When your computer becomes active, start pressing F8 button (if that does not work, try F2, F12, Del, etc. – it all depends on your motherboard model) multiple times until you see the Advanced Boot Options window.
  3. Select Safe Mode with Networking from the list. Windows 7/XP
Windows 10 / Windows 8
  1. Right-click on Start button and select Settings.
  2. Scroll down to pick Update & Security.
    Update and security
  3. On the left side of the window, pick Recovery.
  4. Now scroll down to find Advanced Startup section.
  5. Click Restart now.
  6. Select Troubleshoot. Choose an option
  7. Go to Advanced options. Advanced options
  8. Select Startup Settings. Startup settings
  9. Press Restart.
  10. Now press 5 or click 5) Enable Safe Mode with Networking. Enable safe mode

Step 2. Shut down suspicious processes

Windows Task Manager is a useful tool that shows all the processes running in the background. If malware is running a process, you need to shut it down:

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Click on More details.
    Open task manager
  3. Scroll down to Background processes section, and look for anything suspicious.
  4. Right-click and select Open file location.
    Open file location
  5. Go back to the process, right-click and pick End Task.
    End task
  6. Delete the contents of the malicious folder.

Step 3. Check program Startup

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Go to Startup tab.
  3. Right-click on the suspicious program and pick Disable.

Step 4. Delete virus files

Malware-related files can be found in various places within your computer. Here are instructions that could help you find them:

  1. Type in Disk Cleanup in Windows search and press Enter.
    Disk cleanup
  2. Select the drive you want to clean (C: is your main drive by default and is likely to be the one that has malicious files in).
  3. Scroll through the Files to delete list and select the following:

    Temporary Internet Files
    Recycle Bin
    Temporary files

  4. Pick Clean up system files.
    Delete temp files
  5. You can also look for other malicious files hidden in the following folders (type these entries in Windows Search and press Enter):


After you are finished, reboot the PC in normal mode.

Remove Ryuk using System Restore

To recover your system with System Restore, use the following guide:

  • Step 1: Reboot your computer to Safe Mode with Command Prompt
    Windows 7 / Vista / XP
    1. Click Start Shutdown Restart OK.
    2. When your computer becomes active, start pressing F8 multiple times until you see the Advanced Boot Options window.
    3. Select Command Prompt from the list Select 'Safe Mode with Command Prompt'

    Windows 10 / Windows 8
    1. Press the Power button at the Windows login screen. Now press and hold Shift, which is on your keyboard, and click Restart..
    2. Now select Troubleshoot Advanced options Startup Settings and finally press Restart.
    3. Once your computer becomes active, select Enable Safe Mode with Command Prompt in Startup Settings window. Select 'Enable Safe Mode with Command Prompt'
  • Step 2: Restore your system files and settings
    1. Once the Command Prompt window shows up, enter cd restore and click Enter. Enter 'cd restore' without quotes and press 'Enter'
    2. Now type rstrui.exe and press Enter again.. Enter 'rstrui.exe' without quotes and press 'Enter'
    3. When a new window shows up, click Next and select your restore point that is prior the infiltration of Ryuk. After doing that, click Next. When 'System Restore' window shows up, select 'Next' Select your restore point and click 'Next'
    4. Now click Yes to start system restore. Click 'Yes' and start system restore
    Once you restore your system to a previous date, download and scan your computer with ReimageIntego and make sure that Ryuk removal is performed successfully.

Bonus: Recover your data

Guide which is presented above is supposed to help you remove Ryuk from your computer. To recover your encrypted files, we recommend using a detailed guide prepared by security experts.

If your files are encrypted by Ryuk, you can use several methods to restore them:

Use Data Recovery Pro to unlock lost files

Data Recovery Pro is an effective tool that can be used for recovering lost data. To use it properly, perform these steps:

  • Download Data Recovery Pro;
  • Follow the steps of Data Recovery Setup and install the program on your computer;
  • Launch it and scan your computer for files encrypted by Ryuk ransomware;
  • Restore them.

Try Windows Previous Versions feature to get your files back

If you had System Restore point created before the attack of ransomware happened, try this option to get your data back.

  • Find an encrypted file you need to restore and right-click on it;
  • Select “Properties” and go to “Previous versions” tab;
  • Here, check each of available copies of the file in “Folder versions”. You should select the version you want to recover and click “Restore”.

Ryuk decryptor is not available yet

Finally, you should always think about the protection of crypto-ransomwares. In order to protect your computer from Ryuk and other ransomwares, use a reputable anti-spyware, such as ReimageIntego, SpyHunter 5Combo Cleaner or Malwarebytes

How to prevent from getting ransomware

Protect your privacy – employ a VPN

There are several ways how to make your online time more private – you can access an incognito tab. However, there is no secret that even in this mode, you are tracked for advertising purposes. There is a way to add an extra layer of protection and create a completely anonymous web browsing practice with the help of Private Internet Access VPN. This software reroutes traffic through different servers, thus leaving your IP address and geolocation in disguise. Besides, it is based on a strict no-log policy, meaning that no data will be recorded, leaked, and available for both first and third parties. The combination of a secure web browser and Private Internet Access VPN will let you browse the Internet without a feeling of being spied or targeted by criminals. 

No backups? No problem. Use a data recovery tool

If you wonder how data loss can occur, you should not look any further for answers – human errors, malware attacks, hardware failures, power cuts, natural disasters, or even simple negligence. In some cases, lost files are extremely important, and many straight out panic when such an unfortunate course of events happen. Due to this, you should always ensure that you prepare proper data backups on a regular basis.

If you were caught by surprise and did not have any backups to restore your files from, not everything is lost. Data Recovery Pro is one of the leading file recovery solutions you can find on the market – it is likely to restore even lost emails or data located on an external device.

About the author
Jake Doevan
Jake Doevan - Computer technology expert

If this free removal guide helped you and you are satisfied with our service, please consider making a donation to keep this service alive. Even a smallest amount will be appreciated.

Contact Jake Doevan
About the company Esolutions

Removal guides in other languages