How to Remove Bytelocker Ransomware

On this post is a concise explanation about Bytelocker ransomware. Also provided are Removal Procedures, possible File Decryption of encrypted files, and Methods to Secure the Computer.

Bytelocker ransomware is a highly dangerous crypto-virus. Several security applications may detect it as HiddenTears, AGEN, ZemsilF, FileCoder, or FileCrypter. Once it enters the computer, important files of users will be affected because Bytelocker will encrypt them using an AES-256 method. The goal of people behind this virus is to extort money from victims by requesting them to send payment for the password for file decryption process. Unlike the majority of ransomware, Bytelocker virus will not append the file name so, users will only learn about the attack when the ransom message pop-up on the screen.

How Bytelocker virus enters the computer?

Just like common computer menaces, Bytelocker spreads in various methods and it can penetrate the computer in any directions. Phishing emails, malicious software installer, web injectors, dubious advertisements, and from another Trojan downloader infection. Hence, there is a consensus that the bulk amount Bytelocker ransomware or any infection of this type are acquired from the mass-mailing campaign. This is the common technique by ransomware makers where they are attaching the virus to promising emails and persuade the recipients to open the attached file. Incorrect and careless action of email users will cause Bytelocker to initialize and begin the infection.

Aside from phishing emails, the widespread deployment of Bytelocker ransomware have been so effective with the help of malicious software installers. Victims may have obtained Bytelocker virus from pirated application, malicious freeware, or bogus software update. Having said that, computer users should stay away from illegal distribution of commercial software and as much as possible, limit the downloading of files from official websites and trusted online providers.

Bytelocker File Encryption

As soon as Bytelocker ransomware infects the computer, it scout the local drive for important files. It normally targets day-to-day data like documents, photos, videos, music files, databases, archive files, and similar items. To deny the access of computer users to these selected files, it will use a complex encryption technique particularly applying an AES-256 method.
Bytelocker employs a software-based encryption. The virus resides on the computer and it is able to decrypt and decrypt files using its own cipher scheme. Therefore, it demands victims to pay for the password that will give them access to decryption area of Bytelocker. Here is a complete statement on the graphical interface:

Your personal files are encrypted!
Your important files, documents, pictures, etc. have been encrypted.
Here is a complete list of encrypted files, you can verify this manually.
Encryption was produced using AES-256 in order to decrypt the files, you need to obtain the password used to generate the key.
The password will only be available for a limited time, after this, the program will delete itself and there will be no way to recover encrypted files.
NOTE: Removal or modification of this software will lead to inability to decrypt files.

Screenshot of Bytelocker virus

Technical Details
Threat NameBytelocker Ransomware, HiddenTear
Threat TypeCrypto-virus, File Locker, Encryption Virus
Encryption MethodAES-256 Asymmetric Encryption
Discovered by@GrujaRS
Virus AliasAvira : HEUR/AGEN.1130184
BitDefender : Gen:Heur.Ransom.HiddenTears.1
Emsisoft : Gen:Heur.Ransom.HiddenTears.1 (B)
ESET-NOD32 : A Variant Of MSIL/Filecoder.XL
F-Secure : Heuristic.HEUR/AGEN.1130184
Fortinet : MSIL/Filecoder.TA!tr
Kaspersky : HEUR:Trojan.Win32.Generic
Malwarebytes : Ransom.ByteLocker
Microsoft : Ransom:MSIL/FileCryptor.B!MTB
Rising : Ransom.HiddenTear!8.DC9E (TFE:C:U7lg23t0qaO)
TrendMicro : Ransom.MSIL.BYTELOCKER.SM
ZoneAlarm : EUR:Trojan.Win32.Generic
VMRay : MALWARE RANSOM

For complete details including full detection list, hash file, file names, and technical behavior (registry actions, shell commands, and processes) of Bytelocker ransomware, please refer to this VirusTotal page.

Backup your files

One important step before proceeding with the procedures below is to backup your files. Ransomware are not the same. Each has its unique sets of payloads aside from encrypting the files with complex method. Others tend to delete the infected files after certain period, while others keep them concealed on hidden places. In addition, ransomware decryption tools are not guaranteed to be perfect, there are instances that files suffer from damages during the decryption process.

So, create a backup copy of your entire Bytelocker encrypted files right now.

Bytelocker Ransomware Removal Guide

First thing to do is remove the Bytelocker virus before attempting the decryption. Remember that as long as the ransomware is active, it will repeatedly encrypt the files on the compromised computer.

Infection of Bytelocker ransom virus is dangerous to the system because it can inject files that runs each time Windows starts. To prevent the malicious files from loading, Windows operating system must run with minimal process and it can be done through SafeMode With Networking.

Quick Fix - Scan the PC with Combo Cleaner for Windows

Combo Cleaner is a trusted PC security and optimization tool equipped with powerful virus and malware detection engine. This program can get rid of ransomware like Bytelocker through this procedure.

1. Download the application from the following page:

2. Save the file to your preferred location.

3. Double-click the downloaded file CCSetup.exe and install with the default settings.

CC for Windows Installation

4. At the end of the setup process, click Finish to run Combo Cleaner.

5. The tool will update the signature file, please wait for this process to complete.

6. To begin checking for threats like Bytelocker, click on the Start Scan button. Wait for this scan to finish.

CC for Windows Start Scan

7. At the end of the scan process, click on Remove all threats to delete Bytelocker ransomware including all malicious objects from the computer.

Free features of Combo Cleaner for Windows include Disk Cleaner, Big Files finder, Duplicate files finder, and Uninstaller. To use antivirus, privacy scanner, and to delete identified threats, users have to upgrade to a premium version.

Please continue with the succeeding removal procedures if your are comfortable to manually get rid of the threat and malicious items linked with it.

Stage 1 : Temporarily Disable System Restore on Windows OS

Because Bytelocker and relevant virus is capable of reinstating itself by exploiting the System Restore of Windows, we suggests that you temporary disable System Restore while executing the steps. This option is also helpful to effectively run a full scan on the computer.

Do not forget to enable back System Restore after completing the removal of Bytelocker ransomware. This feature is vital in reinstating the operating system to previous normal working condition in case of problems or conflicts occurs.

Stage 2 : Start Windows in Safe Mode With Networking

Windows 10 Guide

1. Click on Windows logo and select Power icon when options pop-ups.
2. Select Restart from the options while pressing Shift key on the keyboard.
3. Choose an Option window will appear, select the Troubleshoot button.
4. On next window, please choose Advanced Option.
5. On Advanced Option window, click on Startup Settings and then, click Restart button to reboot the computer.
6. When Windows boot on Startup Settings, press function key F5 or number 5 on keyboard.

A simpler alternative for Windows 10 users is to scan the computer with Microsoft Defender Offline. This will run a virus scan in the recovery environment.

Windows 8 Guide

1. Click Windows Start icon at the lower left section of the screen.
2. Open Search window and type Advanced in the field. It will open General PC Settings.
3. Click on Advanced Startup and then, click on Restart Now button.
4. Once the computer starts in Advanced Startup option menu, select Troubleshoot.
5. Next, click on Advanced Options to reveal the next section.
6. Click Startup settings and then, click Restart button to boot the PC in Startup Settings.
7. Use function key F5 or number key 5 to Enable Safe Mode with Networking.

Stage 3 : Scan the Computer with Sophos Antivirus

Ransomware files are placed deeply into the system and on various locations, thus, thorough scanning is vital to totally remove Bytelocker virus. Aside from our suggested tool, you may also run your own security program.

To remove Bytelocker automatically, scanning the computer with this efficient anti-malware tool is suggested. This scanner does not just uncover known threats like viruses or malware, it is also effective in discovering hazardous ransomware like Bytelocker.

1. Download Sophos Virus Removal Tool from the link below. Save the file on your computer where you can easily access it.

2. Once the download completes, browse the location of the file. Double-click to run the program and begin the install process.

3. On first windows of installation wizard, click Next to continue. Then, it will display the program’s License Agreement. You need to Accept the terms in order to proceed. If Windows prompts for User Account Control, please click Yes to proceed.

Screenshot of Sophos EULA Page

4. On succeeding windows, click Next or Continue to carry on with the installation. After completing the installation process, Launch Sophos Virus Removal Tool.

5. Internet connection is required when running this virus scanner in order to download important updates. Make sure that everything is up-to-date to effectively remove Bytelocker ransomware and other relevant viruses.

6. Click the Start Scanning button to inspect the computer. This will check the system for presence of malicious objects, malware, and viruses. The tool reveals items that were found linked to Bytelocker and other suspicious entities. Be sure to remove all identified threats.

Screenshot of Sophos Virus Scan

The above procedures should have totally eliminated Bytelocker ransomware. However, if you found that there are still remnants of the virus, please proceed to succeeding procedures below.

Stage 4 : Double-check with Microsoft's Malicious Software Removal Tool

1. Download the free scanner called Malicious Software Removal Tool.

Download MSRT

2. The tool automatically checks the operating system and suggest appropriate download version. Click on Download button to begin. Save the file to a convenient location, preferably on Desktop.

3. After downloading the file, Windows will prompt that download has completed. Click Run to start scanning for Bytelocker ransomware. Another option is to browse the location folder and double click on the file to run.

MSRT Icon

4. The tool will display Welcome screen, click Next. Please note the message "This tool is not a replacement for an antivirus product." You must understand that this program is made specifically to find and remove malware, viruses, Trojans, and other harmful elements on the computer. It was not designed to protect the computer.

MSRT Welcome

5. Next, you will see Scan Type. Please choose Full Scan to ensure that all Bytelocker ransom virus entities and other harmful files left on the computer will be found and removed. For advanced computer user, you can opt for Customized Scan, if there are other drives or folders you wanted to include in this scan.

MSRT Scan

6. Full scan may take a while, please wait for Malicious Software Removal Tool to complete the tasks. However, you may cancel the scan anytime by clicking on the Cancel button.

MSRT Scan

7. After scanning, the tool will reveal all identified threats. There may be other threats that our first scan fails to detect. Please remove/delete all detected items.

8. When removal procedure is complete, you may now close Malicious Software Removal Tool. We hope that Bytelocker ransomware have been completely deleted from the computer. Please restart Windows to proceed with the normal operation.

Recover Files from Bytelocker Ransomware Infection

On this section, we will provide ways to decrypt files infected with Bytelocker ransomware. Aside from dedicated decryption software and common tools, other options for file recovery are provided. As much as we can, we will update this area whenever there is new and more suitable decryption tool was made available.

Decrypting Bytelocker infected files with Emsisoft Tools

This service from Emsisoft is helpful in unlocking encrypted files without paying the ransom. It gives three ways to detect the ransomware and provide suitable recovery method:

Upload ransom note – This is usually the .txt or .hta files that was generated by Bytelocker ransomware.

Upload the encrypted file – The actual encrypted file. Choose the one that is less than 8MB in size.

Contact information – Enter the email address or any links provided as it appears in the ransom note of Bytelocker virus.

Emsisoft Tools

After submitting any of the appropriate data, Emsisoft will attempt to identify the ransomware and provide keys if there are available.

Option 1: Windows Previous Version Tool

Windows Vista and Windows 7 have a feature called Previous Versions. However, this tool is only usable if restore point was made prior to ransomware infection. To use this tool as "recovery option" for files encypted by Bytelocker virus, please follow these steps:

1. Open My Computer or Windows Explorer.

2. Right-click on the affected files or folders. From the drop-down list, please click on Restore previous versions.

3. New window will open display all backup copy of files and folders you wanted to recover. Choose the appropriate file and click on Open, Copy, or Restore. Restoring selected files overwrites the current locked files on the computer. The tool is not actually recovering files encrypted by Bytelocker. Instead, it restores files from backup copy.

Option 2: Use ShadowExplorer to restore files encrypted by Bytelocker Ransomware

Just like Previous Version tool, ShadowExplorer is taking advantage of shadow copy created by Windows. This tool allows you to retrieve older version of files before it was encrypted by Bytelocker ransomware.

1. Download ShadowExplorer from the official web site.

2. Install the program with the default settings.

3. The program should run automatically after installation. If not, double-click on ShadowExplorer icon.

4. You can see the drop-down list on top of the console. Please select proper drive and the most recent point-in-time shadow copies of files you wish to restore prior to Bytelocker ransomware infection.

shadow3

5. Right-click on the Drive, Folder, or File you wish to restore and click Export...

6. Lastly, ShadowExplorer will prompt for location where you want to save the copy of recovered files.

How to protect the computer from Bytelocker ransomware?

After the removal of the ransomware, it is important to prevent similar incident from happening again. In order to protect the computer effectively, computer user must know how Bytelocker ransomware was able to infect the computer. To minimize the possible infection, staying away from the common sources of this virus is crucial.

How Bytelocker ransomware can infect your computer?

The method of infecting the computers was found to be similar as other common viruses. Though, ransomware like Bytelocker is seen to have efficient deployment via spam email messages, web injectors, malicious software installers, misleading online advertisements, and through another virus infection.

Once the virus is executed, it immediately infects the system. Then, Bytelocker ransomware communicates to remote server so that unique key can be generated for the specific computer. After acquiring the key, it starts to decrypt target files using a complex method that is almost unbreakable. On the last stage of the attack, Bytelocker ransomware demands for ransom money as payment for the decryption tool. To further understand the attack scheme, we have included an infographic below.

Infographic image of ransomware attack stages
You can print, download, or share the infographic by clicking the image.

Securing the computer against ransomware attack

Do a Regular File Back-up - Always backup your data on a separate storage devices such as external hard drives, optical discs, or online backup services.

Keep Your Software Updated - Make sure that you have the latest software updates especially on the operating system. Recent updates often contain vital security patches to help protect the computer against all forms of threats.

Install a Security Program - Protect the computer with effective anti-virus application using efficient real-time scanning. Regularly run a complete scan to check the computer for presence of malware.

Protect your files with Controlled Folder Access (Windows 10)

For Windows 10 users, aside from protecting the computer using anti-virus or anti-malware programs, one way to protect against ransomware attack is by using Controlled Folder Access. This feature of Windows Defender Security Center may not prevent the Bytelocker ransomware infection, but it can protect the folder and files in general. Follow the steps to enable Controlled Folder Access in Windows 10.

1. Go to Windows 10 Taskbar and search for Windows Defender Security Center.

2. Open Windows Defender Security Center and click on Virus & Threat Protection icon.

Virus and Threat Protection

3. On next window, please click on Ransomware Protection.

4. Under Controlled Folder Access section, switch the slider to On. That will enable the feature and protect the folder against Bytelocker or any type of ransomware.

Controlled Folder Access

5. Click on Protected Folderslink to include additional folders. Make sure that folders where important files are located should be included in the list.

Add Protected Folder

Troubleshooting Guide

Certain programs maybe blocked by Controlled Folder Access feature. To fix the issue, simply have the specific program to be white listed.

1. Under Protected Folders, click Allow an app through controlled folder access.

2. Next, click the Add an allowed app and include the target executable file.

This Controlled Folder Access feature is one way to protect files against Bytelocker. Other important things to do in keeping files safe against ransomware is through early prevention like keeping programs updated, install an efficient security program, an do regular file backup on a separate media drive.

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