Also Known As: NOT_OPEN LOCKER virus
Distribution: Low
Damage level: Severe

NOT_OPEN LOCKER ransomware removal instructions


NOT_OPEN LOCKER is a ransomware-type, high-risk virus that was discovered by Jakub Kroustek. This virus is a new variant of Everbe ransomware that stealthily infiltrates systems and encrypts all files. During encryption, NOT_OPEN LOCKER adds the ".[].NOT_OPEN" extension to every affected/encrypted file. For example, a file named "1.jpg" will become "1.jpg.[].NOT_OPEN", and so on. Once NOT_OPEN LOCKER ransomware has encrypted files, it stores a "!_HOW_RECOVERY_FILES_!.txt" file in every folder that contains encrypted files.

The "!_HOW_RECOVERY_FILES_!.txt" file contains a message stating that all users' files have been encrypted (not damaged, only modified). According to the message, these changes can be reverted, but only by receiving a decryption program/key by contacting NOT_OPEN LOCKER developers via an email address (  provided. According to these cyber criminals, they then return full instructions on how to decrypt all files. They even offer free decryption of three files as a 'guarantee' that they will decrypt the remaining files when payment is made/the ransom is paid. The text document does not contain any other information, such as the amount of money to be paid and how quickly, and in which form (for example, Bitcoin or other cryptocurrency). It is also not known whether NOT_OPEN LOCKER developers use a symmetric or asymmetric encryption algorithm. In any case, users require a decryption key to receive their encrypted files. Note that cyber criminals should never be trusted and users should ignore all demands issued by them. Note that cyber criminals often ignore victims and do not send the decryption key even if the ransom is paid. Unfortunately, there are not tools that might be capable of decrypting affected files free of charge. The only solution is to restore them from a backup.

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

NOT_OPEN LOCKER decrypt instructions

Many ransomware-type viruses are very similar to NOT_OPEN LOCKER. For example, Everbe,, Scarab-Hitler, etc. Some are designed by the same cyber criminals, however, most share an identical purpose: to encrypt users' files and make ransom demands. Differences between these viruses are usually cost of decryption and type of encryption algorithm used. Most cyber criminals use RSA, AES, and other similar encryption algorithms that generate unique/individual decryption keys. It impossible to restore encrypted files manually, unless the virus contains bugs or is not fully developed. You are strongly advised to create backups regularly and store them on disconnected/unplugged storage device or use remote storage servers. If not, backups might be encrypted with other regular data.

How did ransomware infect my computer?

There are many different ways that systems become infected by ransomware-type viruses. For example, spam email campaigns, trojan viruses, third party software downloaders, and other similar download sources and fake software updaters. When a spam campaign method is used, cyber criminals send various e-mails to users with attached files (such as MS Office documents, Java Script files, and others). When opened, these files execute scripts that download and install malicious software/malware. Third party software downloaders, free file hosting websites, Peer2Peer (P2P) networks, free software download sites, and other similar sources often contain executable files that are malicious, but are presented as legitimate. In this way, users are often tricked into allowing malware to be downloaded and installed. Trojan is that type of virus which cause chain infections. Therefore, when a trojan has infected the system, it also generates various other viruses. In some cases, systems become infected by ransomware-viruses through fake software updaters that supposedly update outdated software or fix software bugs, however, rather than providing these functions, they download and install malicious software.

Threat Summary:
Threat TypeRansomware, Crypto Virus, Files locker
SymptomsCan't open files stored on your computer, previously functional files now have a different extension, for example my.docx.locked. A ransom demanding message is displayed on your desktop. Cyber criminals are asking to pay a ransom (usually in bitcoins) to unlock your files.
Distribution methodsInfected email attachments (macros), torrent websites, malicious ads.
DamageAll files are encrypted and cannot be opened without paying a ransom. Additional password stealing trojans and malware infections can be installed together with a ransomware infection.

To eliminate NOT_OPEN LOCKER virus our malware researchers recommend scanning your computer with Spyhunter.
▼ Download Spyhunter
Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

How to protect yourself from ransomware infections?

We strongly recommend that you download software using official/trustworthy websites or other sources, and direct links. Avoid using third party downloaders or installers, since these often download rogue applications. Analyze received emails with care and do not open attachments in messages that are sent from unknown or suspicious senders. Use official/implemented tools to update software - these usually are provided by official developers. It is also important to have a probable antivirus software installed and enabled. If your computer is already infected with NOT_OPEN LOCKER, we recommend running a scan with Spyhunter for Windows to automatically eliminate this ransomware.

Text presented in NOT_OPEN LOCKER ransomware "!_HOW_RECOVERY_FILES_!.txt" text file:


Your files are NOT damaged! Your files are modified only. This modification is reversible.
The only 1 way to decrypt your files is to receive the decryption program.

To receive the decryption program write to email:
And in subject write your ID: ID-902d495a94
We send you full instruction how to decrypt all your files.
If we do not respond within 24 hours, write to the email:

Free decryption as guarantee.
We guarantee the receipt of the decryption program after payment.
To believe, you can give us up to 3 files that we decrypt for free.
Files should not be important to you! (databases, backups, large excel sheets, etc.)

Screenshot of files encrypted by NOT_OPEN LOCKER ("[].NOT_OPEN" extension):


NOT_OPEN LOCKER ransomware removal:

Instant automatic removal of NOT_OPEN LOCKER virus: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Spyhunter is a professional automatic malware removal tool that is recommended to get rid of NOT_OPEN LOCKER virus. Download it by clicking the button below:
▼ DOWNLOAD Spyhunter 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 Spyhunter.

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 NOT_OPEN LOCKER 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.

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 NOT_OPEN LOCKER 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 NOT_OPEN LOCKER 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 NOT_OPEN LOCKER 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 NOT_OPEN LOCKER, 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 NOT_OPEN LOCKER ransomware.

Note that Windows 10 Fall Creators Update includes a "Controlled Folder Access" feature that blocks ransomware attempts to encrypt your files. By default, this feature automatically protects files stored in the Documents, Pictures, Videos, Music, Favorites as well as Desktop folders.

Controll Folder Access

Windows 10 users should install this update to protect their data from ransomware attacks. Here is more information on how to get this update and add an additional protection layer from ransomware infections.

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 NOT_OPEN LOCKER ransomware:

About the author:

Tomas Meskauskas

Tomas Meskauskas - expert security researcher, professional malware analyst.

I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats. Contact Tomas Meskauskas.

PCrisk security portal is brought by a company RCS LT. Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.

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Malware activity

Global virus and spyware activity level today:

Medium threat activity

Increased attack rate of infections detected within the last 24 hours.

QR Code
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