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Remove Ryuk ransomware (Virus Removal Instructions) - Sep 2020 update

removal by Jake Doevan - - | Type: Ransomware

Ryuk – the cryptovirus that is developed by the most profitable cybercriminals in the last 6 plus years

Ryuk Ransomware 

Ryuk is a ransomware virus[1] that, since August 2018, has already attacked and encrypted data from several companies, data centers, and PCs. According to numerous speculations, the virus is hailing 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.

Questions about Ryuk ransomware

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 Reimage Reimage Cleaner Intego or SpyHunter 5Combo Cleaner which is capable of destroying all the traces of malware.

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

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.[8] This latest 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 Reimage Reimage Cleaner Intego 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. 

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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.

To remove Ryuk virus, follow these steps:

Remove Ryuk using Safe Mode with Networking

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

  • Step 1: Reboot your computer to Safe Mode with Networking

    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 Safe Mode with Networking from the list Select 'Safe Mode with Networking'

    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 Networking in Startup Settings window. Select 'Enable Safe Mode with Networking'
  • Step 2: Remove Ryuk

    Log in to your infected account and start the browser. Download Reimage Reimage Cleaner Intego or other legitimate anti-spyware program. Update it before a full system scan and remove malicious files that belong to your ransomware and complete Ryuk removal.

If your ransomware is blocking Safe Mode with Networking, try further method.

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 Reimage Reimage Cleaner Intego 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 Reimage Reimage Cleaner Intego, SpyHunter 5Combo Cleaner or Malwarebytes

Access your website securely from any location

When you work on the domain, site, blog, or different project that requires constant management, content creation, or coding, you may need to connect to the server and content management service more often. It is a hassle when your website is protected from suspicious connections and unauthorized IP addresses.

The best solution for creating a tighter network could be a dedicated/fixed IP address. If you make your IP address static and set to your device, you can connect to the CMS from any location and do not create any additional issues for server or network manager that need to monitor connections and activities. This is how you bypass some of the authentications factors and can remotely use your banking accounts without triggering suspicious with each login. 

VPN software providers like Private Internet Access can help you with such settings and offer the option to control the online reputation and manage projects easily from any part of the world. It is better to clock the access to your website from different IP addresses. So you can keep the project safe and secure when you have the dedicated IP address VPN and protected access to the content management system.

Recover files after data-affecting malware attacks

While much of the data can be accidentally deleted due to various reasons, malware is one of the main culprits that can cause loss of pictures, documents, videos, and other important files. More serious malware infections lead to significant data loss when your documents, system files, and images get encrypted. In particular, ransomware is is a type of malware that focuses on such functions, so your files become useless without an ability to access them.

Even though there is little to no possibility to recover after file-locking threats, some applications have features for data recovery in the system. In some cases, Data Recovery Pro can also help to recover at least some portion of your data after data-locking virus infection or general cyber infection. 


About the author
Jake Doevan
Jake Doevan - Computer technology expert

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