Bonsoir Ransomware – Virus Removal Guide

On this page, we are providing a simple explanation about Bonsoir virus. Also included are Removal Guide, possible File Recovery of encrypted files, and Ways to Protect the Computer, as well as Tutorial Video.

Bonsoir ransomware is seemingly a new malware that do not belong to any group of crypto-virus . The objective of this type of malware is to extort money from victims by holding their important files as hostage. In order to achieve this, Bonsoir is going to perform a complex file encryption once it infects the computer. What goes along with this decoding is the renaming process where the virus will append the data with .bonsoir file extension. To cite an example, the common file word.doc will transform into word.doc.bonsoir once the encryption process has completed.

How Bonsoir virus infects the computer?

There are actually a number of ways that attackers are using to deploy Bonsoir ransomware. Per malware researchers’ analysis, the virus can reach the computer via phishing emails, software piracy, infected websites, malicious links, software exploits, and from another Trojan infection. The payload of Bonsoir appears to be exploiting the misconfigured remote desktop protocol (RDP) in order to execute commands and establish a communication to a remote server.

Due to this versatility of the virus, it may be hard for ordinary computer users to guard the target entry point. Sometimes, anti-virus is not enough because Bonsoir ransomware can disable the running process belonging to this security app, making it irresponsive.

Bonsoir File Encryption

When this virus activates on the computer via any means mentioned above, it initializes several stages of attack. At first, Bonsoir ransomware communicates to a remote computer and receive commands from the attacker. It obtains the public key from the said server and will use it during the file encryption process. With the public key on-hand, Bonsoir will begin the encryption using a high-level method that is comparable to military grade technique. Having said that, it seems very impossible for computer users to decrypt the files without acquiring the paid recovery tool and private key that are in the possession of attackers.

Due to the lacking of free or third-party Bonsoir decryption software, the hackers are taking these chances to demand for steeper ransom money. They are going to request for this payment via the ransom note file that are generated on the same folder as the encrypted data. Here is an excerpt from the said documents.

Bonsoir Ransomware
We have to notify you that your device has been infected and all of your files are encrypted This means you cannot access any of your files without purchasing the “Bonsoir Decryptor” from us
The decryption solution is easy: To buy decryptor instantly, you must visit our website using the TOR BROWSER!
1. Download and install the Tor browser on your computer.
2. Visit the our website with Tor browser…
3. Enter Login-Code: [unique code] 4. Takes the necessary steps by following the instructions provided on the our website.
5. We look forward to seeing you on cold winter nights.

Screenshot of Bonsoir ransom note

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 Bonsoir encrypted files right now.

Bonsoir Ransomware Removal Guide

First thing to do is remove the Bonsoir 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 Bonsoir 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.

Stage 1 : Temporarily Disable System Restore on Windows OS

Because Bonsoir 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 Bonsoir 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 Bonsoir virus. Aside from our suggested tool, you may also run your own security program.

To remove Bonsoir 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 Bonsoir.

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.

Screnshot of Sophos Installer

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 Bonsoir 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 Bonsoir and other suspicious entities. Be sure to remove all identified threats.

Screenshot of Sophos Virus Scan

The above procedures should have totally eliminated Bonsoir 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 Bonsoir 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 Bonsoir 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 Bonsoir ransomware have been completely deleted from the computer. Please restart Windows to proceed with the normal operation.

Recover Files from Bonsoir Ransomware Infection

On this section, we will provide ways to decrypt files infected with Bonsoir 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 Bonsoir 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 Bonsoir 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 Bonsoir 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 Bonsoir 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 Bonsoir. Instead, it restores files from backup copy.

Option 2: Use ShadowExplorer to restore files encrypted by Bonsoir 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 Bonsoir 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 Bonsoir 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 Bonsoir 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 Bonsoir ransomware was able to infect the computer. To minimize the possible infection, staying away from the common sources of this virus is crucial.

How Bonsoir ransomware can infect your computer?

The method of infecting the computers was found to be similar as other common viruses. Though, ransomware like Bonsoir 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, Bonsoir 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, Bonsoir 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 Bonsoir 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 Bonsoir 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 Bonsoir. 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.

Tutorial video to remove Bonsoir

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