Mailto ransomware removal instructions

Also Known As: Mailto virus
Distribution: Moderate
Damage level: Severe

Mailto ransomware removal instructions

What is Mailto?

Discovered by GrujaRS, Mailto (also known as NetWalker) is malicious software and an updated version of Kokoklock ransomware. Mailto encrypts files, thereby rendering them unusable. The program encrypts data and renames files with the developer's email address and an extension comprising the victim's unique ID (e.g. ".e85fb1"). For example "1.jpg" might be renamed to "1.jpg.mailto[].e85fb1". Once the encryption is complete, Mailto stores a text file in the format "victim's_ID-Readme.txt" (e.g. "E85FB1-Readme.txt") on the desktop.

The message within the text file informs users that their data was encrypted. To restore it, they are urged to contact the cyber criminals responsible for encryption. Victims are encouraged to contact Mailto's developers via the email addresses provided - this will enable them to learn how to decrypt their files and/or pay the ransom. Each victim with files infected by this ransomware receives a unique ID/personal code detailed within the text file. This code must be included in the email response. Additionally, users are permitted to attach one file free of charge for decryption. Generally, only cyber criminals can decrypt data encrypted with their software. Mailto and similar programs use strong encryptions that are virtually impossible to 'crack'. Note that cyber criminals can never be trusted - they often provide no decryption software/tools even if paid. If ransom demands are met, victims receive nothing in return and data is lost. The only way to recover encrypted files is from a backup, if one was created prior to encryption.

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

Mailto decrypt instructions

Mailto is similar to StuardRitchiCalebSherminator, and many other ransomware-type programs. All encrypt data and demand ransom payments to decrypt files. Differences are cryptographic algorithm used (symmetric or asymmetric) and size of ransom (commonly between three and four digit sums). In most cases, manual decryption (without the involvement of cyber criminals) is impossible unless the ransomware is still in development and/or has flaws/bugs. To ensure data safety, keep backup copies on remote servers and/or unplugged storage devices. As these are also liable to damage, store multiple backups in different locations.

How did ransomware infect my computer?

Ransomware and other malware is proliferated in multiple ways: through trojans, spam campaigns, untrustworthy download channels, software "cracking" (activation) tools and fake updaters. Trojans are malicious programs designed to cause chain infections. They perform rogue download/installation of other malware. Malicious content is also spread through various email attachments (e.g. executable and archive files, Microsoft Office and PDF documents, JavaScript and others). These deceptive emails are sent through large-scale spam campaigns and are often marked as "important" or "official". Untrustworthy download sources also spread malware. These include, Peer-to-Peer sharing networks (e.g. BitTorrent, Gnutella, eMule and etc.), free file hosting websites, third party downloaders and other similar sources. Program "cracking" tools often install malware, rather than activating licensed software. Fake updaters operate in a similar way - rather than updating programs, they exploit bugs/flaws and install malicious content.

Threat Summary:
Name Mailto virus
Threat Type Ransomware, Crypto Virus, Files locker.
Encrypted Files Extension .mailto[] followed by victim's unique ID (e.g., ".mailto[].e85fb1")
Ransom Demanding Message victim's_ID-Readme.txt
Cyber Criminal Contact,,,
Detection Names Avast (Win32:Trojan-gen), BitDefender (Gen:Variant.Razy.553720), ESET-NOD32 (A Variant Of Win32/Filecoder.NXP), Kaspersky (HEUR:Trojan.Win32.Generic), Full List Of Detections (VirusTotal)
Symptoms Cannot open files stored on your computer, previously functional files now have a different extension (for example, my.docx.locked). A ransom demand message is displayed on your desktop. Cyber criminals demand payment of a ransom (usually in bitcoins) to unlock your files.
Distribution methods Infected email attachments (macros), torrent websites, malicious ads.
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 Mailto 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

Attachments included in emails received from suspicious/unknown senders should never be opened. These emails are often disguised as "official", "important", "urgent", or otherwise highlighted as priority mail. In fact, irrelevant emails should not be opened, despite these misleading labels. Download software from official and verified sources only. Do not use unofficial and untrustworthy download websites, Peer-to-Peer sharing networks and other third party downloaders. Software present on the system should be kept up-to-date via functions/tools provided by the official developer. The same extends to software activation. Illegal activation tools ("cracks") might cause system infections. Have a reputable anti-virus/anti-spyware suite installed and updated. These programs can be used to perform regular system scans for detection and elimination of potential threats. If your computer is already infected with Mailto, we recommend running a scan with Spyhunter for Windows to automatically eliminate this ransomware.

Text presented in Mailto ransomware text file ("victim's_ID-Readme.txt"):

What happen ?

Your files are encrypted, and currently unavailable.
You can check it: all files on your computer has expansion e85fb1.
By the way, everything is possible to recover, but you need to follow our instructions.
Otherwise, you cant return your data.

What guarantees?

Its just a business. We absolutely do not care about you and your deals, except getting
benefits. If we do not do our work and liabilities - nobody will not cooperate with us.
Its not in our interests.
To check the ability of returning files, you should write to us by email.
There you can decrypt one file for free. That is our guarantee.

How to contact with us ?

Email us:

Be sure to include your personal code in the letter:

Screenshot of files encrypted by Mailto (random extension):

Files encrypted by Mailto

Update February 6, 2020 - Developers of Mailto (NetWalker) ransomware have recently started targeting various enterprise networks in order to generate huge revenues. Companies are way more likely to have files that are valuable than regular users. In addition, these files often contain various sensitive data (e.g., customers' personal data, product information [like patents, ingredients, and similar), information about employees, etc.) For this reason, there's a way higher probability that company will agree to pay for the decryption and thus blackmailing becomes easier. If that wasn't enough, companies are willing to pay way more money than a home user who wishes to retrieve his music collection, photos, and so forth. In other words, such personal information isn't worth much and crooks are way more likely to generate revenue by blackmailing companies rather than home users. Additionally, an updated version of Mailto ransomware has been released. Its behavior is virtually the same. The only differences are the provided email addresses and message within the ransom note.

Screenshot of the updated Mailto ransomware's note ("random_string-Readme.txt"):

Updated Mailto (NetWalker) ransomware ransom note

Text presented within this file:

Your files are encrypted.
All encrypted files for this computer has extension: .f5be7


If for some reason you read this text before the encryption ended,
this can be understood by the fact that the computer slows down,
and your heart rate has increased due to the ability to turn it off,
then we recommend that you move away from the computer and accept that you have been compromised,
rebooting/shutdown will cause you to lose files without the possibility of recovery and even god will not be able to help you,
it could be files on the network belonging to other users, sure you want to take that responsibility?


Our encryption algorithms are very strong and your files are very well protected, you can't hope to recover them without our help.
The only way to get your files back is to cooperate with us and get the decrypter program.
Do not try to recover your files without a decrypt program, you may damage them and then they will be impossible to recover.

We advise you to contact us as soon as possible, otherwise there is a possibility that your files will never be returned.
For us this is just business and to prove to you our seriousness, we will decrypt you some files for free,
but we will not wait for your letter for a long time, mail can be abused, we are moving on, hurry up with the decision.

Сontact us:

Don't forget to include your code in the email:

Screenshot of files encrypted by the updated Mailto ransomware (random extension remains):

Files compromised by the updated Mailto (NetWalker) ransomware

Screenshot of the updated Mailto ransomware's process (disguised as "Sticky Password") in Windows Task Manager:

Process of the updated Mailto (NetWalker) ransomware

Mailto ransomware removal:

Instant automatic removal of Mailto 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 Mailto 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 Mailto 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 Mailto 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 Mailto 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 Mailto 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 Mailto, 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 Mailto ransomware.

Note that Windows 10 Fall Creators Update includes a "Controlled Folder Access" feature that blocks ransomware attempts to encrypt your files. By default, this feature automatically protects files stored in the 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 is more information on how to get this update and add an 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 Mailto ransomware:

{loadposition position16

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 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.

Our malware removal guides are free. However, if you want to support us you can send us a donation.

Removal Instructions in other languages
Malware activity

Global malware activity level today:

Medium threat activity

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

QR Code
Mailto virus QR code
A QR code (Quick Response Code) is a machine-readable code which stores URLs and other information. This code can be read using a camera on a smartphone or a tablet. Scan this QR code to have an easy access removal guide of Mailto virus on your mobile device.
We Recommend:

Get rid of Mailto virus today:

▼ REMOVE IT NOW with Spyhunter

Platform: Windows

Editors' Rating for Spyhunter:
Editors ratingOutstanding!

[Back to Top]

Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.