A new ransomware was discovered called Zenis Ransomware. What is most disturbing about Zenis is that it not encrypts your files, but also purposely deletes your backups.
How Zenis Ransomware encrypts a computer?
Zenis ransomware is distributed via hacked Remote Desktop services.
When executed, the current Zenis Ransomware variant will perform two checks to see if it should begin encrypting the comptuer. The first check is to see if the file that executed is named iis_agent32.exe, with this check being case insensitive. The other check is to see if a registry value exists called HKEY_CURRENT_USER\SOFTWARE\ZenisService “Active”.
If the registry value exists or the file is not named iis_agent32.exe, it will terminate the process and not encrypt the computer.
If it passes the checks, it will then begin to get the ransom note ready by filling in some information, such as emails and encrypted data.
After that is completed it will execute the following commands to delete the shadow volume copies, disable startup repair, and clear event logs.
Zenis will then search for various processes and terminate them. The processes terminated are:
sql
taskmgr
regedit
backup
When encrypting a file it will change the file name to the following format. Zenis-[2 random chars].[12 random chars]. For example, test.jpg would be encrypted and renamed to something like Zenis-4Q.4QDV9txVRGh4. The original file name and the AES key use to encrypt the file will be encrypted and saved to end of the file.
When looking for files to encrypt, if it finds files associated with backup files, it will overwrite them three times and then delete them. This is to make it more difficult for the victim to restore files from a backup.
While encrypting, it will also create ransom notes named Zenis-Instructions.html in every file that it traverses. This ransom note contains instructions on how to contact the ransomware developer in order to get their files back. The current email addresses included in the ransom notes are TheZenis@Tutanota.com, TheZenis@MailFence.com, TheZenis@Protonmail.com, and TheZenis@Mail2Tor.com.
The reason they ask for the ransom note is because it contains a hidden base64 encoded string that can be decrypted using the private RSA key that only the ransomware developer has possession of. When this data is decrypted, the ransomware developer can decrypt the sample file sent to them or create a decryptor.
How to protect yourself from the Zenis Ransomware?
In order to protect yourself from ransomware in general, it is important that you use good computing habits and security software. First and foremost, you should always have a reliable and tested backup of your data that can be restored in the case of an emergency, such as a ransomware attack.
As Zenis Ransomware may be installed via hacked Remote Desktop services, it is very important to make sure its locked down correctly. This includes making sure that no computers running remote desktop services are connected directly to the Internet. Instead place computers running remote desktop behind VPNs so that they are only accessible to those who have VPN accounts on your network.
It is also important to setup proper account lockout policies so that it makes it difficult for accounts to be brute forced over Remote Desktop Services.
Ransomware Note Contains:-
*** All your files has been encrypted ***
I am ZENIS. A mischievous boy who loves cryptography, hardware and programming. My world is full of unanswered questions and puzzles half and half, and I’m coming to discover a new world. A world in digital space that you are supposed to play the role of my toys.
If you want to win in this game, you have to listen carefully to my instructions, otherwise you will be caught up in a one-step game and you will become the main loser of the story.
My instructions are simple and clear. Then follow these steps:
1. Send this file (Zenis-Instructions.html) to my email with one your encrypted file less than 2 MB to trust to the game.
2. I decrypt your file for free and send for you.
3. If you confirm the correctness of the files, verify that the files are correct via email
4. Then receive the price of decrypting files
5. After you have deposited, please send me the payment details
6. After i confirm deposit, i send you the “Zenis Decryptor” along with “Private Key” to recovery all your files.
Now you can finish the game. You won the game. congratulations.
Please submit your request to both emails:TheZenis@Tutanota.com
TheZenis@MailFence.com
If you did not receive an email after six hours, submit your request to the following emails:
TheZenis@Protonmail.com
TheZenis@Mail2Tor.com (On the TOR network)
Warning: 3rd party and public programs, It may cause irreversible damage to your files. And your files will be lost forever.
All Users are requested to:
- Install and keep NPAV updated up-to-date.
- Make sure NPAV Data Backup is ON.
- Always use trusted and secure sites for downloading setups.