Remove Karl Ransomware (.karl File Infection)

By | Posted on September 22, 2019 | Updated on October 5, 2019

Karl ransomware is a highly dangerous computer threat in which the whole operation is focusing on locking all common users file formats like documents, spreadsheet, database, archives, drawings, photos, videos, and so on. Attackers planned this so that they can demand ransom payment from victims if they need to restore encrypted files to its original form because at the current infected state, data are having .karl file extension. As mentioned, files with this format are unusable and considered to be worthless unless victims properly decrypt them with appropriate method.

Karl ransomware is known to be a representative of recent editions from STOP malware family and it is so unfortunate for victims that malware researchers have yet to find a solution to freely restore files with .karl extension. Unlike old variants that can be decrypted by STOPDecrypter tool, attackers made significant changes to most recent versions of Karl including Kvag, Domn, and Meds. By applying proper asymmetrical encryption to these variants, the offline key decryption method no longer seen as alternative solution to recover .karl files.

Having said that, paying the attacker does not guarantee complete decryption of infected files and so, security experts never recommended it in the first place. Keep in mind that you are dealing with online swindlers who can leave without a mark after taking the ransom money. In addition, people behind Karl ransomware ensures that all transactions when dealing with them remains untraceable and they can achieve this by concealing their activities behind false internet addresses and obscured payment processor using Bitcoin currency.

Karl Ransomware

While waiting for the proper decryption tool to recover Karl files, it is suggested to archive all infected files. Then, proceed with the removal of the virus to avoid infecting new files. Please navigate below for the complete removal procedures.

How to Remove Karl Ransomware

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

Though affected files may be impossible to decrypt due to complexity of the encryption, you can still try recovery method like alternative tool, Shadow Explorer or Previous Version as described below.

Stage 1: Scan the Computer with Anti-Malware Tool

1. Download free anti-malware scanner called MalwareBytes Anti-Malware.
Malwarebytes Anti-Malware Download Link (this will open a new window)

2. After downloading, install the program. It may run automatically or you have to double-click on the downloaded file MB3-Setup-[version].exe.

3. Carry out the installation with default setup process.

4. At the last stage of installation process, click the Finish button. The program should launch momentarily.

5. On Malwarebytes Anti-Malware console, select Scan from the menu to see available Scan Method.

6. Next, click on Threat Scan. This is the most complete scan method that will surely find any hidden malicious objects associated to Karl ransomware.

7. Finally, click on Start Scan begin checking the computer for malware and similar threats.


8. Once the scan has completed, the tool will display the list of detected threats. Remove all identified malicious items and restart the computer if necessary.

Stage 2: Double-check for Karl’s leftover with Microsoft’s Malicious Software Removal Tool

1. Download the free scanner called Malicious Software Removal Tool.
Malicious Software Removal Tool Download Link (this will open a new window)


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 Karl ransomware. Another option is to browse the location folder and double click on the file to run.


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.


5. Next, you will see Scan Type. Please choose Full Scan to ensure that all Karl 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.


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.


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 Karl ransomware have been completely deleted from the computer. Please restart Windows to proceed with the normal operation.

Stage 3 : Unlocking files with Karl Decryption Tool

The Decrypter_2 tool will work only if affected files were encrypted using Offline Keys. Karl ransomware uses the alternate Offline Keys during encryption if there is a problem encountered while communicating to a remote command-and-control server. Follow the guide to start recovering .karl encrypted files.

1. As precautionary measures, we suggest to BACKUP all your .karl encrypted files first on a separate media (USB Drive, Flash Drive, DVD Discs, etc…).

2. Download the Decrypter_2 from this archive page.

3. Double-click on decrypter_2.exe to run the program. Windows may prompt “Do you want to run this app…” just click Yes to continue.

4. Copy and Paste all required information such as the following:

Decrypter 2

5. If decrypting one file only, you do not need to click on Start button. Single file will be decrypted instantly.

6. When decrypting .karl files within a folder, please select Decrypt Folder and then, click Start.

We will update this section once the full decryption tool is on hand. In the meantime, please try other options below.

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 Karl ransomware infection. To use this tool and recover files affected by the 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 encrypted files on the computer.

Option 2: Use ShadowExplorer to restore files encrypted by Karl 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 Karl 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 Karl ransomware infection.


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.

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