GAPO Virus (.GAPO File) 🔐 Decrypt & Removal Guide

The Gapo virus is a member of the STOP/DJVU family of ransomware-type infections. This virus encrypts your files (video, photos, documents) with a specific “.gapo” extension that can be tracked. It employs a strong encryption method, making it impossible to calculate the key in any way.

I have gathered a complete collection of all possible solutions, tips, and practices in neutralizing the Gapo virus and decrypting files. In some cases, it is easy to recover your files. And sometimes it is just impossible.

There are several universal methods for recovering encrypted files, which will be demonstrated below. Reading the entire instruction manual carefully and understanding it all is vital. Do not skip any steps. Each of these steps is very important and must be completed by you.

What isGapo virus?

Gapo

🤔 Gapo virus is ransomware that originates from the DJVU/STOP family. Its primary purpose is to encrypt files that are important for you. After that ransomware virus asks its victims for a ransom fee ($490 – $980) in BitCoin.

The Gapo ransomware is a threat that encrypts your files and compels you to pay for them. Please note that Djvu/STOP ransomware family was first revealed and discovered by virus analyst Michael Gillespie.

Gapo virus is similar to other representatives of the same DJVU family: Xaro, Vapo, Gatq. This virus encrypts all common file types and adds its “.gapo” extension to all files. For instance, the file “1.jpg” will be changed into “1.jpg.gapo“. As soon as the encryption is accomplished, the virus generates a specific text file “_readme.txt” and adds it to all folders that contain the modified files.

The image below gives a clear vision of how encrypted files look like:

Gapo File (STOP/DJVU Ransomware)

Name	Gapo Virus
Ransomware family¹	DJVU/STOP² ransomware
Extension	.gapo
Ransomware note	_readme.txt
Ransom	From $490 to $980 (in Bitcoins)
Contact	[email protected], [email protected]
Detection³	Win32/Agent.UNQ, Win64/Filecoder.BA, LockScreen.Trojan.ScreenLocker.DDS
Symptoms	Encrypted most of your files (photos, videos, documents) and added a particular “.gapo” extension; Can delete Volume Shadow copies to make victim’s attempts to restore data impossible; Adds a list of domains to HOSTS file to block access to certain security-related sites; Installs password-stealing Trojan on the system, like Azorult Spyware;
Fix Tool	To remove possible malware infections, scan your PC: 6-day free trial available.

This text asking payment is for restoring files via decryption key:

_readme.txt (STOP/DJVU Ransomware) – The scary alert demanding from users to pay the ransom to decrypt the encoded files contains these frustrating warnings

Gapo ransomware arrives as a set of processes that are meant to perform different tasks on a victim’s computer. One of the first ones being launched is winupdate.exe, a tricky process that displays a fake Windows update prompt during the attack. This is meant to convince the victim that a Windows update causes a sudden system slowdown. However, simultaneously, the ransomware runs another process (usually named after four random characters) which starts scanning the system for target files and encrypting them. Next, the ransomware deletes Volume Shadow Copies from the system using the following CMD command:

vssadmin.exe Delete Shadows /All /Quiet

Once deleted, it becomes impossible to restore the previous computer state using System Restore Points. The thing is, ransomware operators are getting rid of any Windows OS-based methods that could help the victim to restore files for free. In addition, the crooks modify the Windows HOSTS file by adding a list of domains and mapping them to the localhost IP. As a result, the victim will run into a DNS_PROBE_FINISHED_NXDOMAIN error when accessing one of the blocked websites.

We noticed that ransomware attempts to block websites that publish various how-to guides for computer users. By restricting specific domains, the crooks are trying to prevent the victim from reaching relevant and helpful ransomware-attack-related information online. The virus also saves two text files on the victim’s computer that provide attack-related details – the victim’s public encryption key and personal ID. These two files are called bowsakkdestx.txt and PersonalID.txt.

After all these modifications, the malware doesn’t stop. Variants of STOP/DJVU tend to drop password-stealing trojans like Vidar Stealer or RedLine Stealer. Those threats has a lengthy list of capabilities, such as:

Stealing Steam, Telegram, Skype login/password;
Stealing cryptocurrency wallets;
Downloading malware to the computer and running it;
Stealing browser cookies, saved passwords, browsing history, and more;
Viewing and manipulating files on victim’s computer;
Allowing the hackers to remotely perform other tasks on the victim’s computer.

The cryptography algorithm used by DJVU/STOP virus is AES-256. So, if your data got encrypted with an online decryption key, which is unique. Sadly, it is only possible to decrypt the files with the unique key.

If Gapo worked online, it is impossible for you to gain access to the AES-256 key. It is stored on a distant server owned by the frauds who promote the Gapo ransomware.

The payment should be $980 for receiving the decryption key. To obtain the payment details, the victims are encouraged by the message to contact the frauds by email ([email protected]).

The message by the ransomware states the following information:

ATTENTION!

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:

https://we.tl/t-WJa63R98Ku

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:

[email protected]

Reserve e-mail address to contact us:

[email protected]

Your personal ID:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Do not pay for Gapo!

Please, try to use the available backups, or Decrypter tool

The readme.txt file also indicates that the computer owners must contact the Gapo representatives within 72 hours from the moment the files were encrypted. If you get in touch within 72 hours, the Gapo representatives will grant you a 50% rebate, reducing the ransom amount to $490. However, it is strongly advised to avoid paying the ransom!

I strongly advise you not to contact these frauds and not to make any payments. One of the most effective solutions to recover lost data is to use the available backups or the Decrypter tool. You can find more information on how to decrypt Djvu ransomware files here.

All such viruses have the peculiarity of applying a similar set of actions to generate the unique decryption key for recovering the encrypted data.

Therefore, unless the ransomware is still under development or has some hard-to-track flaws, manually recovering the encrypted data is impossible. The only solution to prevent the loss of your valuable data is to regularly back up your crucial files.

Note that even if you maintain such backups regularly, they should be stored in a specific location without lingering or being connected to your main workstation.

The backup can be kept on a USB flash drive or an alternative external hard drive storage. Alternatively, you can use online (cloud) information storage for backup.

It goes without saying that when you store your backup data on your primary device, it can be encrypted just like other data.

Therefore, it is not wise to keep the backup on your main computer.

How I was infected?

Ransomware has various methods to built into your system. But it doesn’t really matter what concrete method was used in your case.

Gapo ransomware attack following a successful phishing attempt.

Nevertheless, these common leaks may inject it into your PC:

Hidden installation occurs along with other apps, especially the utilities that work as freeware or shareware.
A dubious link in spam emails leads to the virus installer.
Online free hosting resources.
Using illegal peer-to-peer (P2P) resources to download pirated software.

Cases have occurred where the Gapo virus was disguised as a legitimate tool. For example, it may appear in messages demanding the initiation of unwanted software or browser updates. This is typically how some online frauds attempt to force you into manually installing the Gapo ransomware, making you directly participate in this process.

Certainly, the bogus update alert will not indicate that you will inject the virus. This installation will be concealed under an alert stating that you supposedly need to update Adobe Flash Player or some other dubious program.

Cracked apps also represent a source of damage. Using P2P is both illegal and can result in the injection of serious malware, including the Gapo ransomware.

To sum up, what can you do to avoid injecting the Gapo ransomware into your device? Although there is no 100% guarantee to prevent damage to your PC, there are specific tips I want to give you to prevent Gapo penetration. You must be cautious when installing free software today.

Always make sure you read what the installers offer in addition to the main free program. Stay away from opening suspicious email attachments. Do not open files from unknown addresses. Of course, always keep your current security program updated.

The malware does not openly announce itself. It will not be listed among your available programs. However, it will be masked under a malicious process that runs regularly in the background, starting from the moment you launch your PC.

How To Remove Gapo Virus?

In addition to encoding a victim’s files, the Gapo infection has also started to install the Azorult Spyware on system to steal account credentials, cryptocurrency wallets, desktop files, and more.⁴

Reasons why I would recommend GridinSoft⁵

How To Decrypt .gapo Files?

Restore solution for big “.gapo files“

Try removing .gapo extension on a few BIG files and opening them. Either the Gapo ransomware read and did not encrypt the file, or it bugged and did not add the filemarker. The latter is most likely if your files are very large (2GB+). Please, let me know in the comments if that will work for you.

The newest extensions were released around the end of August 2019 after the criminals made changes. This includes Gatz, Gash, Qore, etc.

As a result of the changes made by the criminals, STOPDecrypter is no longer supported. It has been removed and replaced with the Emsisoft Decryptor for STOP Djvu Ransomware developed by Emsisoft.

You can download free decryption tool here: Decryptor for STOP Djvu.

Select folders for decryption.

Based on the default settings, the decryptor will automatically populate the available locations to decrypt the currently available drives (the connected ones), including the network drives. Extra (optional) locations can be selected with the help of the “Add” button.

Decryptors suggest several options considering the specific malware family. The current options are presented in the Options tab and can be activated or deactivated there. You may locate a detailed list of the currently active Options below.

Click on the “Decrypt” button.

As soon as yo add all the desired locations for decryption into the list, click on the “Decrypt” button to initiate the decryption procedure.

Note that the main screen may turn you to a status view, letting you know of the active process and the decryption statistics of your data:

The decryptor will notify you once the decryption procedure is completed. If you need the report for your papers, you can save it by choosing the “Save log” button. Note that it is also possible to copy it directly to your clipboard and paste it into emails or messages here if necessary.

The Emsisoft Decryptor might display different messages after a failed attempt to restore your Gapo files:

✓ Error: Unable to decrypt file with ID: [your ID]

There is no corresponding decryption key in the Emsisoft decryptor’s database.

✓ No key for New Variant online ID: [your ID]

Notice: this ID appears to be an online ID, decryption is impossible

Your original files were encrypted with an online key. So no one else has the same encryption/decryption key pair. Recovery of gapo files without paying the criminals is impossible. 🙁

✓ Result: No key for new variant offline ID: [example ID]

This ID appears to be an offline ID. Decryption may be possible in the future.

An offline key was used, but files could not be restored (the offline decryption key isn’t available yet). But, receiving this message is good news for you because restoring your Gapo files in the future might be possible. 🙂
It can take a few weeks or months until the decryption key gets found and uploaded to the decryptor. Please follow updates regarding the decryptable DJVU versions here.

✓ Remote name could not be resolved

It’s an indication of a DNS issue on your PC. Our first recommendation is to reset your HOSTS file back to default.

How to Restore .gapo Files?

In some case, Gapo ransomware is not doom for your files…

Gapo ransomware encryption mechanism feature is next: it encrypts every file byte-by-byte, then saves a file copy, deleting (and not overriding!) the original file. Hence, the file location information on the physical disk is lost, but the original file is not deleted from the physical disk. The cell, or the sector where this file was stored, can still contain this file, but the file system does not list it and can be overwritten by data that has been loaded to this disk after the deletion. Hence, it is possible to recover your files using special software.

I recently had my pc infected by the Gapo virus. It managed to bypass 2 Antivirus software and 2 malware fighters.

Anyway, after realizing it was an online algorithm, it is impossible to retrieve my encrypted files. I also had my backup drive plugged in at the time of the virus, and this was also infected, or so I thought. Every folder within my backup drive had been infected and was encrypted. However, despite losing some important files, I retrieved almost 80% of my 2TB storage.

When I started going through the folders, I noticed the readme.txt ransom note in every folder. I opened some of the folders and found that all files that were not in a subfolder within that folder had been encrypted. However, I found a flaw and a glimmer of hope when I went into the subfolders in other folders and found that these files needed to be encrypted. Every folder within my c and d drives, including subfolders, had been encrypted, but this was not the case with the backup drive. Having subfolders created within a folder has saved 80% of my data.

As I said, this is only a small loophole on a backup drive. I’ve since found 10% of my data on another hard drive on a different pc. So my advice is if you use a backup drive, create subfolders. I was lucky, I guess. But I was also unlucky that the virus hit as I transferred some files from my backup.

Hopefully, this can help others in my situation.

Jamie Newland

Some pointers for recovery repair of Gapo files (true for all STOP/DJVU variants):

I have seen Gapo variants fail to encrypt deeper nested folders so you can check that. You may find those need to be encrypted.

This ransomware saves encrypted data to a new file and deletes the original. So there’s a slight chance part of that deleted file can be recovered using file recovery software. It’s unlikely the folder structure can be restored, so a free tool like PhotoRec may be as good as any.

This ransomware only partially encrypts (about the first 150 KB), so the not encrypted part may be recoverable depending on file size and type of data.

Joep

Recovering your files with PhotoRec

PhotoRec is an open-source program which is originally created for files recovery from damaged disks or for files recovery in case if they are deleted. However, as time has gone by, this program got the ability to recover the files of 400 different extensions. Hence, it can be used for data recovery after the ransomware attack

At first, you need to download this app. It is 100% free, but the developer states there is no guarantee that your files will be recovered. PhotoRec is distributed in a pack with other utilities of the same developer – TestDisk. The downloaded archive will have TestDisk name, but don’t worry. PhotoRec files are right inside.

To open PhotoRec, you need to find and open “qphotorec_win.exe” file. No installation is required – this program has all the files it needs inside of the archive. Hence, you can fit it on your USB drive and try to help your friend/parents/anyone who was attacked by DJVU/STOP ransomware.

After the launch, you will see the screen showing you the full list of your disk spaces. However, this information is likely useless, because the required menu is placed a bit higher. Click this bar, then choose the disk which was attacked by ransomware.

After choosing the disk, you need to choose the destination folder for the recovered files. This menu is located at the lower part of the PhotoRec window. The best desicion is to export them on USB drive or any other type of removable disk.

Then, you need to specify the file formats. This option is located at the bottom, too. As it was mentioned, PhotoRec can recover the files of about 400 different formats.

Finally, you can start files recovery by pressing the “Search” button. You will see the screen where the results of the scan and recovery are shown.

Gapo files recovery guide

Frequently Asked Questions

🤔 How can I open “.gapo” files?

No way. These files are modified by ransomware. The contents of .gapo files are not available until they are decrypted.

🤔 Gapo files contain important information. How can I decrypt them urgently?

If your data remaining in the .gapo files are very valuable, you made a backup copy. If not, then you can try to restore them through the system function – Restore Point. All other methods will require patience.

🤔 You have advised using GridinSoft Anti-Malware to remove Gapo. Does this mean that the program will delete my encrypted files?

Of course not. Your encrypted files do not pose a threat to the computer. What happened has already happened.

🤔 Gapo virus has blocked the infected PC: I can’t get the activation code.

In this situation, you need to prepare the memory stick with a pre-installed

🤔 Decryptor did not decrypt all my files, or not all of them were decrypted. What should I do?

Have patience. You are infected with the new version of STOP/DJVU ransomware, and decryption keys have not yet been released. Follow the news on our website. We will keep you posted when new Gapo keys or new decryption programs appear.

🤔 What can I do right now?

The Gapo ransomware encrypts only the first 150KB of files. So MP3 files are rather large. Some media players (Winamp for example) may be able to play the files, but – the first 3-5 seconds (the encrypted portion) will be missing. You can try to find a copy of an original file that was encrypted: Files you downloaded from the Internet that were encrypted, and you can download again to get the original.