Cube Ransomware

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

Cube ransomware removal instructions

What is Cube?

Discovered by Michael Gillespie, Cube is classified as a ransomware-type program. When a computer is infected, files become unusable. Cube is designed to encrypt data and keep it locked unless a ransom is paid. It also renames all encrypted files by adding the ".cube" extension. For example, "1.jpg" becomes "1.jpg.cube". Details about how to recover files are provided in a ransom message within a text file called "READ_ME.txt". This file can be found in each folder that contains encrypted data.

The ransom messages states that, in order to decrypt files, victims must contact Cube's developers via the or email address. They should then name the cost of a decryption tool and provide details about how to pay. Most cyber criminals accept cryptocurrency (Bitcoins) only. Before making payment, victims are permitted to send a file, which is then decrypted and returned free of charge. Criminals offer free decryption as so-called 'proof' that they have the correct decryption tool and can be trusted. Nevertheless, do not trust them. After payment is made, most cyber criminals ignore victims and send no decryption tools or keys as promised. Unfortunately, only specific ransomware developers can provide the tools required for successful decryption. Ransomware-type programs encrypt data using cryptography algorithms (symmetric or asymmetric) that make decryption without using the correct tool impossible. There is no free software able to unlock files encrypted by Cube, at least not at the moment. In most cases, the only way to recover files without paying is by restoring them using data backups.

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

Cube decrypt instructions

Cube is just one of many ransomware-type programs. Other examples are SDEN, SadComputer, and Browec. Typically, these programs have two main purposes: to encrypt data and urge victims to pay a ransom. Main differences between these malicious programs are cost of decryption and cryptography used to cause the encryption. Unfortunately, most ransomware-type programs cause encryptions that cannot be decrypted without contacting cyber criminals. In most cases, this situation can be avoided only if the ransomware is still in development, has bugs/flaws, and so on. Therefore, maintain regular backups and store them on remote servers such as Cloud or unplugged storage devices.

How did ransomware infect my computer?

It is unknown which method Cube's developers use to proliferate this malicious software, however, most cyber criminals use spam campaigns, Trojans, unofficial, dubious software download sources, software 'cracking' tools, and unofficial (fake) software updaters. Spam campaigns might be used to proliferate computer infections by sending emails that include malicious attachments. Attached files are usually Microsoft Office documents, archives (ZIP, RAR, and others), PDF documents, executables (.exe files) and JavaScript files, however, they could also be other file formats. The main goal of these campaigns is to trick recipients into opening attached files. If opened, they install high-risk viruses such as ransomware. Trojans are used to proliferate other infections. If a Trojan is installed, it will download and install other malicious programs. Dubious software download sources such as freeware download websites, free file hosting pages, Peer-to-Peer networks (torrent clients, eMule and others) might be used to present various infected files as legitimate and harmless. By opening files downloaded from these sources, people risk installing computer infections. Software 'cracking' tools are programs that supposedly activate paid software free of charge, however, they often install malicious programs. Fake software updaters often download and install malware rather than fixes/updates, or they exploit bugs/flaws of installed software that is out of date.

Threat Summary:
Name Cube virus
Threat Type Ransomware, Crypto Virus, Files locker.
Encrypted Files Extension .cube
Ransom Demanding Message READ_ME.txt text file
Cyber Criminal Contact,
Symptoms Cannot open files stored on your computer, previously functional files now have a different extension (for example, my.docx.locked). A ransom demand message is displayed on your desktop. Cyber criminals demand payment of a ransom (usually in Bitcoins) to unlock your files.
Distribution methods Infected email attachments (macros), torrent websites, malicious ads.
Damage All 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 Cube 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?

Avoid using unofficial websites and third party tools to download software. The safest way to download software is using official websites and direct links. Update installed software using implemented functions or tools that are provided by official software developers. Attachments and web links that are presented in emails received from unknown, suspicious addresses should not be opened, at least not without being sure that it is safe to do so. These emails tend to be irrelevant to the recipient. Furthermore, do not use third party programs to bypass paid software activation. This is illegal and often leads to installation of malware. Finally, have reputable anti-spyware or anti-virus software installed and keep it enabled. These programs detect and remove threats and prevent them from causing any damage. If your computer is already infected with Cube, we recommend running a scan with Spyhunter for Windows to automatically eliminate this ransomware.

Text presented in Cube ransomware text file "READ_ME.txt":

I am truly sorry to inform you that all your important files are crypted.
If you want to recover your encrypted files you need to follow a few steps.
You need to buy bitcoins and send them to the address you receive by mail.
How to obtain Bitcoins
The easiest way to buy bitcoins is LocalBitcoins site.You have to register, click 'Buy bitcoins', and select the seller by payment method and price.
Also you can find other places to buy Bitcoins and beginners guide here:
write to Google how to buy Bitcoin in your country?
in order to guarantee the availability of our key
we can decrypt one file for free
the size of the files  
other formats will not be free decryption
after payment we will send a decryption program
Do not try to decrypt your files with programs by the decoder,
you will only damage your data and lose them forever.
Only we can decrypt your data, write to the original mails specified in this file,
otherwise you will become a victim of scammers.
Contact email address or

Screenshot of files encrypted by Cube (".cube" extension):

Files encrypted by Cube

Cube ransomware removal:

Instant automatic removal of Cube 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 Cube 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 Cube 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 Cube 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 Cube 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 Cube 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 Cube, 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 Cube ransomware.

Note that the 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 Cube 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
Cube virus QR code
A QR code (Quick Response Code) is a machine-readable code which stores URLs and other information. This code can be read using a camera on a smartphone or a tablet. Scan this QR code to have an easy access removal guide of Cube virus on your mobile device.
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Platform: Windows

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