What is RYUK Ransomware
RYUK Ransomware is virulent ransomware threat, based on the code of Hermes 2.1 and BitPaymer viruses. Researchers believe, that famous Lazarus Group is responsible for the development and implementation of the virus. RYUK Ransomware uses RSA-4096 and AES-256 encryption algorithms to encrypt user files and creates RyukReadMe.txt file with following content:
Short version of RYUK ransom note:
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
No system is safe
Long version of RYUK ransom 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.
No system is safe
Hackers demand 15-50 BTC for decryption, which is great amount. RYUK Ransomware does not bypass UAC, requires permission to run, which means user granted access to the computer for virus executable file. Ransomware encrypts all files except ones in following folders: “Windows”, “Mozilla”, “Chrome”, “RecycleBin”, “Ahnlab”. Before the onset of destructive activity, malware stops more than 180 services and 40 processes, by using taskkill and net stop commands. Stopped services and processes mainly belong to antivirus software, running databases, software for backup and editing documents that can prevent file encryption. RYUK also tries to encrypt network resources. The name of the network resource found is added via a semicolon to the list, which will later be used to encrypt these network resources. At the end of encryption, Ryuk destroys its encryption key and launches a BAT file that will remove shadow copies and various backup files from the disk. Use this guide to remove RYUK Ransomware and decrypt affected files.
How RYUK Ransomware infected your PC
Can be distributed by hacking through an unprotected RDP configuration, fraudulent downloads, exploits, web injections, fake updates, repackaged and infected installers. Virus assigns certain ID with the victims, that is used to name those files and supposedly to send decryption key. In order to prevent infection with this type of threats in future we recommend you to use SpyHunter and BitDefender Anti-Ransomware.
Download RYUK Ransomware Removal Tool
To remove RYUK Ransomware completely we recommend you to use SpyHunter from EnigmaSoftware Group LLC. It detects and removes all files, folders and registry keys of RYUK Ransomware.
How to remove RYUK Ransomware manually
It is not recommended to remove RYUK Ransomware manually, for safer solution use Removal Tools instead.
RYUK Ransomware files:
RYUK Ransomware registry keys:
How to decrypt and restore your files
Use automated decryptors
Use following tool from Kaspersky called Rakhni Decryptor, that can decrypt your files. Download it here:
There is no purpose to pay the ransom, because there is no guarantee you will receive the key, but you will put your bank credentials at risk.
If you are infected with RYUK Ransomware and removed it from your computer you can try to decrypt your files. Antivirus vendors and individuals create free decryptors for some crypto-lockers. To attempt to decrypt them manually you can do the following:
Use Stellar Phoenix Data Recovery Pro to restore your files
- Download Stellar Phoenix Data Recovery Pro.
- Select location to scan for lost files and click Scan button.
- Wait until Quick and Deep scans finish.
- Preview found files and restore them.
Using Windows Previous Versions option:
- Right-click on infected file and choose Properties.
- Select Previous Versions tab.
- Choose particular version of the file and click Copy.
- To restore the selected file and replace the existing one, click on the Restore button.
- In case there is no items in the list choose alternative method.
Using Shadow Explorer:
- Download Shadow Explorer program.
- Run it and you will see screen listing of all the drives and the dates that shadow copy was created.
- Select the drive and date that you want to restore from.
- Right-click on a folder name and select Export.
- In case there is other dates in the list choose alternative method.
If you are using Dropbox:
- Login to the DropBox website and go to the folder that contains encrypted files.
- Right-click on the encrypted file and select Previous Versions.
- Select the version of the file you wish to restore and click on the Restore button.
How to protect computer from viruses like RYUK Ransomware in future
1. Get special anti-ransomware software
Use Bitdefender Anti-Ransomware
Famous antivirus vendor BitDefender released free tool, that will help you with active anti-ransomware protection, as additional shield to your current protection. It will not conflict with bigger security applications. If you are searching complete internet security solution consider upgrading to full version of BitDefender Internet Security 2018.
2. Back up your files
Regardless of success of protection against ransomware threats, you can save your files using simple online backup. Cloud services are quite fast and cheap nowadays. There is more sense using online backup, than creating physical drives, that can get infected and encrypted when connected to PC or get damaged from dropping or hitting. Windows 10 and 8/8.1 users can find pre-installed OneDrive backup solution from Microsoft. It is actually one of the best backup services on the market, and has reasonable pricing plans. Users of earlier versions can get acquainted with it here. Make sure to backup and sync most important files and folders in OneDrive.
3. Do not open spam e-mails and protect your mailbox
Malicious attachments to spam or phishing e-mails is most popular method of ransomware distribution. Using spam filters and creating anti-spam rules is good practice. One of the world leaders in anti-spam protection is SpamFighter. It works with various desktop applications, and provides very high level of anti-spam protection.