Locked_file Ransomware

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

Locked_file ransomware removal instructions

What is Locked_file?

Discovered by malware security researcher, Leo, Locked_file is a ransomware-type virus that stealthily infiltrates systems and encrypts stored data. In doing so, Locked_file renames encrypted files using the "[8_random_characters]-[8_random_characters]-[8_random_characters]-[8_random_characters].[restoreassistant2@tutanota.com].locked_file" pattern. For instance, "sample.jpg" might be renamed to a filename such as "GHKA8el9-jgke68AL-InO5Nbk9-OLbgj34a.[restoreassistant2@tutanota.com].locked_file". Following successful encryption, Locked_file creates an HTML file ("!HOW_TO_UNLOCK_FILES!.html"), placing it on the desktop, and a number of other files (for example, "flist.lst", and "errlog.txt"), placing them in each folder containing encrypted files.

The HTML file contains a text message that informs victims of the encryption and that files can only be restored using a unique "decryption tool". Unfortunately, this information is accurate. It is currently unknown which algorithm (symmetric or asymmetric) Locked_file ransomware uses. In any case, decryption requires a unique key. Locked_file's developers store decryption keys on a remote server and generate revenue by blackmailing victims to receive them. To receive a decryption tool (with the key embedded within), victims are instructed to contact developers via an email address provided. They are also permitted to attach a number of selected files, which are decrypted free of charge and returned as a 'guarantee' that their files can actually be restored. These actions must be performed within 72 hours following encryption, otherwise the decryption keys are permanently deleted. After contacting cyber criminals, victims are encouraged to pay a ransom. The cost is currently unconfirmed, but usually fluctuates between the equivalent of $500 and $1500 in Bitcoins. Bear in mind that cyber criminals cannot be trusted - they often ignore victims once payments are submitted. Paying does not guarantee that your files will ever be decrypted and you will probably be scammed. Therefore, never contact cyber criminals or pay any ransom. Unfortunately, there are currently no tools capable of restoring files encrypted by Locked_file and 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:

Locked_file decrypt instructions

Locked_file shares many similarities with dozens of other ransomware-type viruses such as, for example, Scarab, GRYPHON, Aleta, and many others. All have identical behavior - they encrypt data and make ransom demands. In fact, there are just two major differences between this type of malware: 1) size of ransom, and; 2) type of cryptography used. Research shows that most ransomware-type viruses use algorithms that generate unique decryption keys. Therefore, unless the malware is not fully developed (and has bugs/flaws), file decryption manually (without involvement of developers (contacting these people is not recommended) is impossible. Malware such as Locked_file presents a strong case for maintaining regular data backups.

How did ransomware infect my computer?

Cyber criminals proliferate ransomware in various ways, however, the most common are spam emails (infectious attachments), third party software download sources (freeware download websites, free file hosting websites, peer-to-peer networks, etc.), fake software update tools, and trojans. Spam emails often contain attachments (for example, JavaScript files, MS Office documents, etc.) designed to download and install malware. Unofficial software download sources often proliferate malware by presenting it as legitimate software. In doing so, criminals often trick victims into running malicious executables. Fake software updaters exploit outdated software bugs/flaws to infect the system and trojans open 'gates' for other viruses.

How to protect yourself from ransomware infections?

The main reasons for computer infections are lack of knowledge and careless behavior. Therefore, be cautious when browsing the Internet. Delete all suspicious email messages and never open files received from suspicious/unrecognizable email addresses. Furthermore, download your software from official sources only using the direct download URL. If you are forced to use a third party downloader, carefully analyze each step (especially the "Custom/Advanced" settings) and decline offers to download/install additional applications. Note also that third party downloaders often conceal malicious apps, thereby preventing users from canceling their installations. If you are forced to use these tools, cancel the entire process. Furthermore, keep installed applications up-to-date and use a legitimate anti-virus/anti-spyware suite. The key to computer safety is caution.

Text presented in Locked_file ransomware HTML file ("!HOW_TO_UNLOCK_FILES!.html"):

All your files have been encrypted with strong cryptographic algorithm!

It means you will not be able to access them anymore until they are decrypted with your unique decryptor!
If you will follow our instructions, we guarantee that you can decrypt all your files quickly and safely!

Attention! You have only 72 hours for reaction. After this time your unique decryption key will be deleted!

If you want to restore your files, please write us to the e-mail:
For fast authentication you can send us few files for free decryption and your personal ID:

* Do not rename encrypted files.
* Do not try to uninstall the program or run antivirus software.
* Do not try to decrypt your data using third party software, it may cause permanent data loss.
* Decoders of other users are incompatible with your data, each user has unique encryption key.
* For assurance you can send us up to 3 files for free decryption.
* Please note that files for free decryption must NOT contain valuable information and their total size must be less than 5Mb.

The appearance of a pop-up once the infection is started (GIF):

Locked_file ransomware startup pop-up gif

Screenshot of files encrypted by Locked_file ransomware ("[8_random_characters]-[8_random_characters]-[8_random_characters]-[8_random_characters].[restoreassistant2@tutanota.com].locked_file" filename pattern):

Files encrypted by Locked_file

Locked_file 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 Locked_file 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
Locked_file 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 Locked_file 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 Locked_file 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 Locked_file 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 Locked_file, 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 Locked_file 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 Locked_file ransomware: