Elimination of Mtogas ransomware-type infection

Also Known As: Mtogas virus
Distribution: Low
Damage level: Severe

Mtogas ransomware removal instructions

What is Mtogas?

Belonging to Djvu ransomware family, Mtogas is yet another high-risk infection that is firstly developed by Michael Gillespie. The purpose of this infection is to infiltrate computers and to compromise (encrypt data), and keep it that way unless a ransom is paid. Mtogas is also designed to rename each file by adding ".mtogas" extension (for instance, it would rename "1.jpg" to "1.jpg.mtogas" and so on so forth. Once Mtogas finishes file modifications, it generates a text file named "_readme.txt" and drops its copies in all existing folders.

Now almost all infections from Djvu family deliver the exact same ransom-demanding message and Mtogas is one of them. The delivered message basically says that files are compromised and that recovery requires a unique key. Unluckily, this is true. Mtogas employs encryption algorithms that generate unique decryption key individually for each victim. What's more important is that victims cannot access their keys as all of them are stored in a remote server that belongs to developers of Mtogas. Thus, since crooks are the only ones who can access decryption keys, they can easily blackmail victims. In order to receive a key each victim has to pay a ransom of $980. Yet victims are offered a 50% discount with one condition: they have to contact crooks within first 72 hours after the encryption. Crooks also offer a free decryption of one file as a proof that they're actually capable of restoring data. Nevertheless, even if you can afford paying, you should never do so. Vast majority of ransomware developers are scammers - they do not provide any decryption tools/keys after payments are submitted. In other words, they simply ignore victims and paying gives no positive result. For this reason, all encouragements to submit payments, as well as contact these persons should be ignored. Now it is very important to note that Mtogas is designed to check whether the infected machine has Internet connection and if the server is responding. If not, data will be encrypted with a so-called "offline key", which is hard-coded. The same key is used for multiple encryptions and, for this reason, we highly recommend to try restoring data with a decryption tool developed by Michael Gillespie. If that doesn't work, then the only possible solution will be to restore everything from a backup, if there is one created.

Screenshot of a message encouraging users to pay a ransom to decrypt their compromised data:

Mtogas decrypt instructions

Mtogas has very similar characteristics to ERIS RANSOMWARE v2, BORISHORSE, Junior, and dozens of other ransomware infections. Despite the fact that developers are different, all of these infections behave virtually the same. Most of ransomware-type infections are designed to serve only one purpose: to compromise data (typically, by encrypting) so that developers could make ransom demands. There typically are only two major differences: size of ransom and type of encryption algorithm. Unfortunately, encryptions are often performed using AES, RSA, and other high-end algorithms that generate unique decryption keys. Therefore, if the virus is fully developed and/or has no certain bugs/flaws, restoring data manually (without developers interference) is virtually impossible. The only possible scenarios are ransomware not being fully developed and/or having certain bugs/flaws. Ransomware is one of the main reasons why you should maintain regular data backups. However, be sure to store them in a remote server or either unplugged storage device, because locally stored backups will be compromised together with regular data. Moreover, keep in mind that there's always a chance that used server/storage device will be damaged. For this reason, it is advised to have multiple backup copies stored in different locations.

How did ransomware infect my computer?

Ransomware-type infections are usually proliferated by using the following tools/methods: fake software updaters and cracks, trojans, spam emails, and unofficial software download sources. Fake software updaters usually infect computers by abusing outdated software's bugs/flaws or simply downloading and installing malware rather than actual/promised updates. Same goes for fake cracking tools which infect systems rather than providing users with access to software's paid features. Trojans are basically malicious applications that stealthily infiltrate computers and inject them with additional malware afterwards. Next go email spam campaigns, which cyber criminals use to send hundreds of thousands of emails consisting of malicious attachments and deceptive messages presenting attachments as important documents (e.g., invoices, bills, receipts, and similar) and encouraging recipients to open. Last but not least are third party download sources, which are also used in a similar manner. Crooks present malicious executables as legitimate software, thereby tricking recipients into manual download/installation of malware.

Threat Summary:
Name Mtogas virus
Threat Type Ransomware, Crypto Virus, Files locker
Detection Names Avast (Win32:PWSX-gen [Trj]), BitDefender (Trojan.Worm.GenericKDS.32249538), ESET-NOD32 (A Variant Of Win32/Kryptik.GVKO), Kaspersky (Trojan.Win32.Zenpak.htz), Full List Of Detections (VirusTotal)
Encrypted Files Extension .mtogas
Ransom Demanding Message _readme.txt
Ransom Amount $980/$490
Cyber Criminal Contact gorentos@bitmessage.ch, gorentos2@firemail.cc
Symptoms Can't open files stored on your computer, previously functional files now have a different extension, for example my.docx.locked. A ransom demanding message is displayed on your desktop. Cyber criminals are asking to pay a ransom (usually in bitcoins) to unlock your files.
Additional Information This malware is designed to show fake Windows Update window, modify Windows "hosts" file (to prevent users from accessing cyber security websites) and inject AZORult trojan into the system.
Distribution methods Infected email attachments (macros), torrent websites, malicious ads, unofficial activation and updating tools.
Damage All files are encrypted and cannot be opened without paying a ransom. Additional password stealing trojans and malware infections can be installed together with a ransomware infection.

To eliminate Mtogas virus our malware researchers recommend scanning your computer with Spyhunter.
▼ Download Spyhunter
Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

How to protect yourself from ransomware infections?

In order to prevent this situation users must firstly realize that the main reasons for computer infections are poor knowledge and reckless behavior. The key to its safety is caution and, therefore, paying attention when browsing the Internet, as well as downloading/updating/installing software is a must. Always handle all email attachments with care. If the file/link is irrelevant or the sender looks suspicious/unrecognizable then do not open anything. Desired software should be downloaded only from official sources, preferably using direct download links. Similar rules apply to software updates. Keeping installed applications and operating system up-to-date is a must. Yet updates should be performed only by using implemented functions or tools provided by the official developer. Unofficial download/update/installation tools are likely to include rogue applications and, thus, such tools should never be used. It is also worth noting that software piracy is a cyber crime. Moreover, the risk of infections is extremely high, due to the fact that vast majority of these tools are fake. For this reason, you should never attempt to activate software by using unofficial/illegal tools. Lastly, be sure to always have a reputable anti-virus/anti-spyware suite installed and running - it will help you detect and eliminate malware before it harms the system. If your computer is already infected with Mtogas, we recommend running a scan with Spyhunter for Windows to automatically eliminate this ransomware.

Text presented in Mtogas ransomware's text file ("_readme.txt"):


Don't worry, 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.
You can get and look video overview decrypt tool:
Price of private key and decrypt software is $980.
Discount 50% available if you contact us first 72 hours, that's price for you is $490.
Please note that you'll never restore your data without payment.
Check your e-mail "Spam" or "Junk" folder if you don't get answer more than 6 hours.

To get this software you need write on our e-mail:

Reserve e-mail address to contact us:

Your personal ID:

Screenshot of files encrypted by Mtogas (".mtogas" extension):

Files encrypted by Mtogas

Malware researcher Michael Gillespie has developed a decryption tool that might restore your data if it was encrypted using an "offline key". As we've already mentioned, each victim gets a unique decryption key and all of them are stored in remote servers controlled by cyber criminals. These are categorized as "online keys". However, there are cases when the infected machine has no Internet connection or the server is timing out/not responding. If that is the case, Mtogas will use an "offline encryption key", which is hard-coded. Now it is worth mentioning that cyber criminals change offline keys every now and again. This is being done to prevent multiple encryptions with the same key. Meanwhile, Michael Gillespie continually gathers offline keys and updates the decrypter. However, the chances of successful decryption are still very low, since only a very small portion of "offline keys" has been gathered. You can download the decrypter by clicking this link (note that the download link remains the same, despite the fact that decrypter is being continually updated). Your files will be restored only if the list of gathered keys will include the one that was used to encrypt your data.

Screenshot of STOP/Djvu decrypter by Michael Gillespie:

STOP/Djvu ransomware decrypter by Michael Gillespie

As with most of ransomware from Djvu family, Mtogas also displays a fake Windows update pop-up during the encryption:

Djvu ransomware family fake update

IMPORTANT NOTE! - Aside from encrypting data, ransomware-type infections from Djvu malware family also installs a trojan-type virus called AZORult, which is designed to steal various account credentials. Moreover, this malware family is designed to add a number of entries to the Windows hosts file. The entries contain URLs of various websites, most of which are related to malware removal. This is carried out with the intention of making users unable to access malware security websites and seek help. Our website (PCrisk.com) is also on the list. Removing these entries, however, is simple - you can find detailed instructions in this article (note that, although the steps are shown in the Windows 10 environment, the process is virtually identical on all versions of the Microsoft Windows operating system).

Screenshot of websites added to Windows hosts file:

Tro Ransomware adding websites to Windows Hosts file

Mtogas ransomware removal:

Instant automatic removal of Mtogas virus: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Spyhunter is a professional automatic malware removal tool that is recommended to get rid of Mtogas virus. Download it by clicking the button below:
▼ DOWNLOAD Spyhunter By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

Quick menu:

Step 1

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in "Safe Mode with Networking":

Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in "Safe Mode with Networking":

Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button. In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.

windows 10 safe mode with networking

Video showing how to start Windows 10 in "Safe Mode with Networking":

Step 2

Log in to the account infected with the Mtogas virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.

If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.

Video showing how to remove ransomware virus using "Safe Mode with Command Prompt" and "System Restore":

1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.

Boot your computer in Safe Mode with Command Prompt

2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.

system restore using command prompt type cd restore

3. Next, type this line: rstrui.exe and press ENTER.

system restore using command prompt rstrui.exe

4. In the opened window, click "Next".

restore system files and settings

5. Select one of the available Restore Points and click "Next" (this will restore your computer system to an earlier time and date, prior to the Mtogas ransomware virus infiltrating your PC).

select a restore point

6. In the opened window, click "Yes".

run system restore

7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining Mtogas ransomware files.

To restore individual files encrypted by this ransomware, try using Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of Mtogas are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.

To restore a file, right-click over it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the "Restore" button.

Restoring files encrypted by CryptoDefense

If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode making its removal complicated. For this step, you require access to another computer.

To regain control of the files encrypted by Mtogas, you can also try using a program called Shadow Explorer. More information on how to use this program is available here.

shadow explorer screenshot

To protect your computer from file encryption ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and EasySync CryptoMonitor, which artificially implant group policy objects into the registry to block rogue programs such as Mtogas ransomware.

Note that Windows 10 Fall Creators Update includes "Controlled Folder Access" feature that blocks ransomware attempts to encrypt your files. By default this feature automatically protects files stored in Documents, Pictures, Videos, Music, Favorites as well as Desktop folders.

Controll Folder Access

Windows 10 users should install this update to protect their data from ransomware attacks. Here's more information on how to get this update and add additional protection layer from ransomware infections.

HitmanPro.Alert CryptoGuard - detects encryption of files and neutralises any attempts without need for user-intervention:

hitmanproalert ransomware prevention application

Malwarebytes Anti-Ransomware Beta uses advanced proactive technology that monitors ransomware activity and terminates it immediately - before reaching users' files:

malwarebytes anti-ransomware

  • The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups. More information on online backup solutions and data recovery software Here.

Other tools known to remove Mtogas ransomware:

About the author:

Tomas Meskauskas

Tomas Meskauskas - expert security researcher, professional malware analyst.

I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for pcrisk.com since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats. Contact Tomas Meskauskas.

PCrisk security portal is brought by a company RCS LT. Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.

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Malware activity

Global virus and spyware activity level today:

Medium threat activity

Increased attack rate of infections detected within the last 24 hours.

QR Code
Mtogas virus QR code
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Platform: Windows

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