May Ransomware

Also Known As: May virus
Distribution: Low
Damage level: Severe

May ransomware removal instructions

What is May?

May is a ransomware-type virus discovered by MalwareHunterTeam. Once infiltrated, May encrypts various data using AES-256 and RSA-4096 encryption algorithms and appends filenames with the ".locked" extension (for example, "sample.jpg" is renamed to "sample.jpg.locked"). May then creates a text file ("Restore_your_files.txt") containing a ransom-demand message and places it in each folder containing encrypted files.

The message informs victims of the encryption and make ransom demands of 1 Bitcoin (approximately, $1750) in exchange for file decryption. As mentioned above, May employs AES and RSA cryptographies and, therefore, decryption without unique keys is impossible. Cyber criminals store these keys on a remote server and victims are encouraged to pay ransoms to receive them. Research shows, however, that paying does not guarantee that your files will ever be decrypted. Cyber criminals often ignore victims once payments are submitted. There is a high probability that you will be scammed. In addition, you will support cyber criminals' malicious businesses. We strongly advise you to ignore all requests to contact these people or pay any ransom. Unfortunately, there are no tools capable of cracking the aforementioned algorithms and restoring files encrypted by May. Therefore, you can only restore your files/system from a backup.

Screenshot of a message encouraging users to pay a ransom to decrypt their compromised data:

May decrypt instructions

Research reveals dozens of ransomware-type viruses virtually identical to May including Amnesia, ThunderCrypt, and RSAUtil - these are just some examples from many. Note that, as with May, these malware infections also encrypt files and make ransom demands. There are just two major differences: 1) type of encryption algorithm [symmetric/asymmetric] used, and; 2) cost of decryption. Ransomware-type viruses are usually distributed using spam emails (infectious attachments), peer-to-peer networks (torrents, eMule, etc.), third party software download sources (free file hosting websites, freeware download websites, etc.), fake software update tools, and trojans. Therefore, be very cautious when opening files received from suspicious emails, and when downloading software from unofficial sources. Furthermore, keep your installed apps up-to-date, however, note that criminals proliferate malware via fake updaters. Therefore, never update installed applications via third party tools. Using a legitimate anti-virus/anti-spyware suite is also paramount. Rushing and lack of knowledge are the main reasons for computer infections. The key to computer safety is caution.

Message presented within May text file ("Restore_your_files.txt"):

You have 5 days for decrypt your files.
All your files have been encrypted with May Ransomware.
For encrypt we use AES256+RSA4096.
Don`t try recover your files.
Decrypt instruction!
1) Make your bitcoin wallet on or and buy 1 bitcoins on BTC Exchange Sites (
2) Send 1 bitcoin to address 3Gw6b57A3E34nAph3mzGbKAj8sTSgD8GP9
3) Write to us on email . In subject write this identificator "81ff05bf2ab1406d8f11b866e804af37"
4) After receive bitcoins and your email , we contact with you.
YOU MIGHT DECRYPT 2 FILES FOR FREE. Send it to email .In Subject ,write your UNIQUE Identificator.

Screenshot of files encrypted by May (".locked" extension):

Files encrypted by May

May ransomware removal:

Quick menu:

Step 1

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in "Safe Mode with Networking":

Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in "Safe Mode with Networking":

Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button. In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.

windows 10 safe mode with networking

Video showing how to start Windows 10 in "Safe Mode with Networking":

Step 2

Log in to the account infected with the May virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.

Download recommended remover for
May virus

1) Download and install   2) Run system scan   3) Enjoy your clean computer!
By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Reimage.

If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.

Video showing how to remove ransomware virus using "Safe Mode with Command Prompt" and "System Restore":

1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.

Boot your computer in Safe Mode with Command Prompt

2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.

system restore using command prompt type cd restore

3. Next, type this line: rstrui.exe and press ENTER.

system restore using command prompt rstrui.exe

4. In the opened window, click "Next".

restore system files and settings

5. Select one of the available Restore Points and click "Next" (this will restore your computer system to an earlier time and date, prior to the May ransomware virus infiltrating your PC).

select a restore point

6. In the opened window, click "Yes".

run system restore

7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining May ransomware files.

To restore individual files encrypted by this ransomware, try using Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of May are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.

To restore a file, right-click over it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the "Restore" button.

Restoring files encrypted by CryptoDefense

If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode making its removal complicated. For this step, you require access to another computer.

To regain control of the files encrypted by May, you can also try using a program called Shadow Explorer. More information on how to use this program is available here.

shadow explorer screenshot

To protect your computer from file encryption ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and EasySync CryptoMonitor, which artificially implant group policy objects into the registry to block rogue programs such as May ransomware.

HitmanPro.Alert CryptoGuard - detects encryption of files and neutralises any attempts without need for user-intervention:

hitmanproalert ransomware prevention application

Malwarebytes Anti-Ransomware Beta uses advanced proactive technology that monitors ransomware activity and terminates it immediately - before reaching users' files:

malwarebytes anti-ransomware

  • The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups. More information on online backup solutions and data recovery software Here.

Other tools known to remove May ransomware: