Tro Ransomware

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

Tro ransomware removal instructions

What is Tro?

Like most ransomware-type infections, Tro is designed to encrypt data and keep it in this state unless a ransom is paid (a decryption tool/key is purchased). This malicious program is a new variant of Djvu ransomware and was discovered by Michael Gillespie. During the encryption process, the virus displays a fake Windows Update pop-up window and disables Task Manager. Once encryption is complete, all files are renamed by adding the ".tro" extension. For instance, "1.jpg" becomes "1.jpg.tro". A ransom message can be found in the "_openme.txt" text file.

The "_openme.txt" ransom-demand message states that cyber criminals have used Tro ransomware to encrypt all data stored on the computer using the strongest encryption. To access their files, victims are encouraged contact developers via or and provide the assigned unique/personal ID. These criminals should then supposedly provide further details on how to proceed with decryption. They state that only they can provide victims with the decryption tool (this is likely to be accurate). Most cyber criminals use cryptography algorithms (symmetric or asymmetric) that generate unique keys. Typically, these are the only tools that can decrypt the data, however, cyber criminals store them on remote servers and only they have access. Tro ransomware developers offer free decryption of one file as 'proof' that they can be trusted and have the tool required to decrypt files encrypted by Tro. They also offer a 50% discount for victims who make contact within 72 hours following infection. They also warn those with affected computers not to use any other decryption tools, since this might cause permanent data loss. There are no tools capable of free decryption and, therefore, we recommend that you use an existing data backup and restore everything from there. Do not contact Tro's developers or pay any ransom - most cyber criminals ignore victims once their ransom demands are met.

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

Tro decrypt instructions

Tro shares similarities with other ransomware-type programs such as Pdff, XARCryptor, Ahihi, and many others. Typically, these viruses are used to encrypt data stored on computers and make ransom demands. The encrypted files cannot be decrypted without the involvement of ransomware developers, unless the virus is still in development or contains unfixed bugs/flaws. Any differences between these programs are usually cost of decryption tool (key) and cryptography algorithm used for data encryption. The number of ransomware-type infections is growing daily and, therefore, we recommend that you create regular backups and keep them stored on unplugged devices or remote servers. Backups stored on an infected computer are likely to be encrypted with other data.

How did ransomware infect my computer?

Generally, cyber criminals proliferate ransomware-type infections through trojans, spam email campaigns, fake software updaters, and untrustworthy software download sources. Trojans are categorized as malware (malicious programs) designed to cause chain infections. If installed, the proliferate other viruses, including ransomware. Spam campaigns send emails that contain malicious attachments. Computers become infected when users open these attachments, resulting in download and installation of ransomware or other infections. The presented attachments could be Microsoft Office documents, archive files (such as ZIP, RAR), executable files (.exe), PDF documents, and so on. Fake updaters cause computer infections by exploiting bugs/flaws of installed, outdated software or by downloading and installing malicious programs (viruses) rather than the promised/expected updates. Untrustworthy, unofficial websites, free file hosting, freeware download websites, third party downloaders, peer-to-peer networks (such as torrent clients), etc. also proliferate ransomware. Cyber criminals employ these sources to present infected files as legitimate. Using these dubious tools, people risk downloading and installing viruses rather than their chosen software (or other files). In this way, ransomware developers trick users into installing computer infections.

Threat Summary:
NameTro virus
Threat TypeRansomware, Crypto Virus, Files locker
SymptomsCan'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.
Distribution methodsInfected email attachments (macros), torrent websites, malicious ads.
DamageAll 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 Tro 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?

To prevent computer infection by ransomware-type programs or other threats, take certain precautions. Do not open attachments (or websites) that are presented in emails received from dubious, unknown, suspicious addresses, or if the email context does not concern you or is irrelevant. Update software using implemented tools or functions provided by official developers. Download software using official and trustworthy websites. Avoid using software installers, downloaders, and other such tools - these are used to proliferate rogue apps. Have a reputable anti-virus or anti-spyware suite installed and keep it enabled at all times. These tools can detect computer infections before they proliferate and cause any damage. If your computer is already infected with Tro, we recommend running a scan with Spyhunter for Windows to automatically eliminate this ransomware.

Text presented in Tro ransomware text file ("_openme.txt"):

------------------------------------ ALL YOUR FILES ARE ENCRYPTED ------------------------------

Don't worry, you can return all your files!
All your files documents, photos, databases 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 do we give to you?
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 download video overview decrypt tool:
Don't try to use third-party decrypt tools because it will destroy your files.
Discount 50% available if you contact us first 72 hours.


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

Reserve e-mail address to contact us:

Your personal ID:

Screenshot of the fake Windows Update pop-up displayed during the encryption process:

fake windows update pop-up window appearing during Tro encryption process

Screenshot of files encrypted by Tro (".tro" extension):

Files encrypted by Tro

Update January 16, 2019 - Cyber criminals have recently released an updated version of Tro ransomware, which has some additional features. The updated version now disables Windows Defender real-time monitoring by executing a PowerShell command. In addition, the new variant adds 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 ( 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

Update January 17, 2019 - Michael Gillespie has updated his STOPDecrypter, which is now capable of restoring data with the following extensions: ".djvu", ".djvuq", ".djvur", ".djvut", ".djvuu", ".pdff", ".tfude", ".tfudeq", ".tro", ".udjvu", and ".tfudet". You can download the decrypter by clicking this link.

Screenshot of the STOPDecrypter:

STOPDecrypter by Michael Gillespie

Michael states that users should take note of the following:

This decrypter currently only works for personal ID 6se9RaIxXF9m70zWmx7nL3bVRp691w4SNY8UCir0 (the offline key used if the malware failed to get a key from its server), or if you have the key.

If you were provided a key by kNN or myself, you may enter it via the Settings -> Set Djvu Key option; note that entering anything incorrect to this will destroy data, so don't try to be "clever". For "Personal ID", it will accept either the 40 character string at the end of files (not the one in braces, the string just before that), or the 43 character string in the ransom note. The bruteforcer will also explicitly reject this variant, as there is no way of bruteforcing the key at the present time; so don't even waste your time trying to fool it (the feature is for the .puma* variants, and isn't really a "bruteforce" anyways).

The decrypter will only attempt to decrypt a file with a known ID (either the hardcoded one or one you provide with a key); any others will be reported and logged, with instructions to archive it in hopes of future decryption.

If the decrypter detects IDs it could not decrypt, it will display them, along with your MAC addresses for easy archiving (assuming it is ran from the infected PC). It is also logged for you.

Tro ransomware removal:

Instant automatic removal of Tro 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 Tro 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 Tro 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 Tro 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 Tro 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 Tro 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 Tro, 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 Tro 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 Tro ransomware: