Geek's Advice

MOSK ransomware is the 180th version of STOP, decryptable if offline key was used

MOSK ransomware is the newest addition to STOP/DJVU ransomware family. It is a malicious file-encrypting computer virus designed for Windows operating systems. Once installed, it disables firewalls and starts encrypting personal files on each folder, adding .mosk file extensions to them. To finalize the malicious operation, the virus creates a ransom note called _readme.txt, installs Azorult password-stealing Trojan and deletes Volume Shadow Copies from the PC.

MOSK ransomware is developed with the intention to infect computers and take victim’s personal files hostage. To learn how to recover lost data, the victim has to read a ransom note left in each folder with corrupted data. As usual, the note suggests contacting criminals via one of the provided emails and paying a sum of money in Bitcoin cryptocurrency.

The price of the ransom varies depending on how fast the victim manages to pay. If he does it within 72 hours, the ransom cost is $490. Otherwise, it increases to $980. As explained in the ransom note _readme.txt, the victim has to contact criminals via salesrestoresoftware@firemail.cc or salesrestoresoftware@gmail.com to receive instructions and Bitcoin wallet to pay.

It is generally recommended NOT to pay the ransom. However, it is your decision based on how important data was to you. You must remember that there is still a chance to never see your files even after paying up, so keep that in mind.

Threat Summary

Is it possible to decrypt your files?

To address the issue of how to decrypt files with .mosk extension, we must explain how the ransomware operates first. When it scans your computer for target files, it attempts to establish a connection with its remote server, which generates and sends an online key to encrypt data. If the connection is not available or gets lost, an offline key is used then. In the future, the offline key might appear and you will be able to recover your files.

STOP Decrypter already supports .MOSK extension, so if your personal ID or one of them ends with t1, you can recover all or part of your data for free. See instructions how to use the decryption tool here.

You can determine if your files were encrypted with the offline key if your personal ID ends with t1. Otherwise, it means that an online key was used, and there are no chances to decrypt your data. Also, STOP Decrypter won’t work for you.

The first thing you need to do after a ransomware attack is to remove MOSK file virus as soon as you can. Please use the guidelines provided at the end of this article to do it properly. Make sure you update your security software so that it could wipe this STOP DJVU version along with Azorult trojan out from your PC.

Distribution means and ways to avoid file-encrypting viruses

Ransomware can be distributed in various ways. To be precise, STOP/DJVU ransomware versions such as MOSK, DERP, TOEC, and COOT tend to infect target systems in a way that requires user interaction. To be specific, you can easily fall victim to this malware strain if you tend to download illegal software activation tools to get licensed products for free.

In other words, software cracks, keygens and other means of stealing is a no-no and can likely carry a malicious payload. Although many victims suggest they didn’t do anything and ransomware corrupted their files out of thin air, it isn’t true.

Besides, you should know that ransom-demanding viruses are also actively distributed via malicious spam and vulnerabilities in outdated software. For instance, if you’re using an old Windows version with Flash Player technology on it, you can easily be attacked if you visit an infected website online (exploit kit attack type).

Remove MOSK virus and recover your files

Remove MOSK ransomware using virus removal guidelines provided below. These explain how to prepare a safe and clean environment for malware removal. Of course, we recommend doing it automatically using a trustworthy antivirus tool rather than attempting to trace malicious remains manually.

Again, we’d like to remind you that there are no ways to restore .mosk files without having data backups. If you’re lucky and your files were locked with an offline key, don’t hesitate and follow the instructions on how to use STOP Decrypter. Now, concentrate on MOSK removal, which is described below.

OUR GEEKS RECOMMEND

Our team recommends a two-step rescue plan to remove ransomware and other remaining malware from your computer, plus repair caused virus damage to the system:

STEP 1. REMOVE AUTOMATICALLY WITH ROBUST ANTIVIRUS

REMOVE & PROTECT WITH INTEGO

Get INTEGO ANTIVIRUS for Windows to remove ransomware, Trojans, adware and other spyware and malware variants and protect your PC and network drives 24/7.. This VB100-certified security software uses state-of-art technology to provide protection against ransomware, Zero-Day attacks and advanced threats, Intego Web Shield blocks dangerous websites, phishing attacks, malicious downloads and installation of potentially unwanted programs.

Use INTEGO Antivirus to remove detected threats from your computer.

Read full review here.

STEP 2. REPAIR VIRUS DAMAGE TO YOUR COMPUTER

DOWNLOAD RESTORO

RESTORO provides a free scan that helps to identify hardware, security and stability issues and presents a comprehensive report which can help you to locate and fix detected issues manually. It is a great PC repair software to use after you remove malware with professional antivirus. The full version of software will fix detected issues and repair virus damage caused to your Windows OS files automatically.

RESTORO uses AVIRA scanning engine to detect existing spyware and malware. If any are found, the software will eliminate them.

Read full review here.

GeeksAdvice.com editors select recommended products based on their effectiveness. We may earn a commission from affiliate links, at no additional cost to you. Learn more.

Alternative software recommendations

Malwarebytes Anti-Malware

Removing spyware and malware is one step towards cybersecurity. To protect yourself against ever-evolving threats, we strongly recommend purchasing a Premium version of Malwarebytes Anti-Malware, which provides security based on artificial intelligence and machine learning. Includes ransomware protection. See pricing options and protect yourself now.

System Mechanic Ultimate Defense

If you're looking for an all-in-one system maintenance suite that has 7 core components providing powerful real-time protection, on-demand malware removal, system optimization, data recovery, password manager, online privacy protection and secure driver wiping technology. Therefore, due to its wide-range of capabilities, System Mechanic Ultimate Defense deserves Geek's Advice approval. Get it now for 50% off. You may also be interested in its full review.

Disclaimer. This site includes affiliate links. We may earn a small commission by recommending certain products, at no additional cost for you. We only choose quality software and services to recommend.

Norbert Webb

Norbert Webb is the head of Geek’s Advice team. He is the chief editor of the website who controls the quality of content published. The man also loves reading cybersecurity news, testing new software and sharing his insights on them. Norbert says that following his passion for information technology was one of the best decisions he has ever made. “I don’t feel like working while I’m doing something I love.” However, the geek has other interests, such as snowboarding and traveling.