Remove Lanset Ransomware (.lanset Decryption)

By | Posted on June 4, 2019 | Updated on June 11, 2019

Lanset Ransomware is a virus that is equally dangerous to other variants of STOP malware. It encrypts files on infected computer using sophisticated RSA 1024-bit algorithms. Locked files are appended with .lanset and since no software is associated with this type, users may not be able to open it. A picture file pic1.jpg will become pic1.jpg.lanset after the encryption and the same will happen to other file types that are in the range of Lanset virus.

Entry way of this ransom malware is often via spam email messages that purports to be from prominent organizations and companies. Message content is usually a message that persuades recipient to open the attached file. Once executed, Lanset will drop several executable files on the computer with individual functions. It also adds registry entries to run its malicious code each time Windows starts and stays as a running process during computer operation.

Once fully operational, Lanset will look for targeted files and encrypts them individually. This process will have obvious effect on system performance and to avoid suspicion, it will display a fake status report citing that slowdown is due to current Windows update. Below is how the fake Windows update and infected files looks like.

Lanset Fake Update

.Lanset Files

After the encryption, Lanset ransomware will leave a ransom note on each folder with encrypted files. Inside the ransom note are ways to decrypt files and required amount needed in order for victims to obtain the unique key and official decryption tool for Lanset. Here is an excerpt from the ransom note:

ATTENTION!
Don’t worry my friend, you can return all your files!
All your files like photos, databases, documents and other important are encrypted with strongest encryption and unique key.
The only method of recovering files is to purchase decrypt tool and unique key for you.
This software will decrypt all your encrypted files.
What guarantees you have?
You can send one of your encrypted file from your PC and we decrypt it for free.
But we can decrypt only 1 file for free. File must not contain valuable information.

How to Remove Lanset Ransomware

Ransomware files are placed deeply into the system and on various locations, thus, thorough scanning is vital to totally remove Lanset 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 Shadow Explorer or Previous Version as described below.

Stage 1: Scan the Computer with ESET Rogue Application Remover (ERAR)

1. Download the free scanner called ESET Rogue Application Remover.
Download Link for ERAR (this will open a new window)

2. Choose appropriate version for your Windows System. 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 the program. Another option is to browse the location folder and double click on the file ERARemover_.exe.

errar1

4. On ESET Rogue Application Remover SOFTWARE LICENSE TERMS, click Accept to continue.

5. The tool will start scanning the computer. It will prompt when it finds Lanset virus and other malicious entities. Follow the prompt to proceed with the removal.

ERAR

Stage 2: Double-check for Lanset’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)

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 Lanset. 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.

msrt1

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

msrt2

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.

msrt3

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

Stage 3 : Unlocking files with Lanset Decryption Tool

So far, this Lanset decryption tool works only for files that were encrypted using offline keys. This happens sometimes if the virus is unable to communicate to remote server to obtain unique keys; instead, it will use offline keys when encrypting files. However, there is a little chance of recovering files using this tool due to limited available offline keys that were integrated with this decryption tool. You may download StopDecrypter (by Demoslay335) from this website.

We will update this section once the full decryption tool is on hand. In the meantime, please try the 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 Lanset virus 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 Lanset

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 Lanset.

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 Lanset 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.

Leave a Reply

Your email address will not be published. Required fields are marked *