SAGE Virus File — How to Decrypt & Remove Ransomware

The Sage virus, also known as a ransomware infection, belongs to the STOP/DJVU family. This malware family is famous for its malicious file encryption capabilities. Once the Sage virus gets into a system, it targets various types of files, such as photos, videos, documents, and more. It modifies the file structure and appends the “.sage” extension to each encrypted file, making them inaccessible and unusable without the decryptor.

Sage Virus Overview

Sage

🤔 Sage malware belongs to ransomware that belongs to the DJVU/STOP ransomware family. Its primary purpose is to cipher files that are important to you. After that ransomware virus asks for a ransom payment – ($499 – $999) in Bitcoin.

The Sage virus is a malicious program that encrypts your files and coerces you into paying for their decryption. This ransomware encrypts different file types. ciphered files become identifiable by a distinct “.sage” extension. As a result, the affected files become inaccessible and unusable.

Then, the ransomware asks for a file decryption payment in Bitcoin from the victims, ranging from $499 to $999. Usually, a text file with ransom payment guidances is named as “_readme.txt“.

Sage Ransomware uses Salsa20 encryption algorithms to cipher the files. Since Sage virus employs such a strong ciphering method, it becomes pretty difficult, if not impossible, to pick the decryption key without cooperating with the attackers.

Once Sage malware finishes the encryption, it shows a ransom note to the victim, demanding a ransom payment in exchange for the decryption key. The ransom note provides instructions on how to make the payment and often includes threats of data loss or increased ransom amounts if the ransom is not paid within a specified timeframe.

I have made a comprehensive list of the solutions, tips, and practices to remove the Sage virus and decrypt your files. In some cases, it may be possible to restore your files, but sometimes, it may be impossible.

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📌 Important Note!

It is critical to voice that paying the ransom does not guarantee the successful recovery of your files. The hackers who stand behind the Sage virus are not trustworthy. There were the cases where victims have paid the ransom, only to be denied by the cybercriminals with the decryption key provision.

Sage employs a unique key for each victim, with one exception:

If Sage fails to connect the command and control server (C&C) before starting the encryption process, it resorts to using offline keys. An offline key is not unique and is the same for all users, allowing for the decryption of files encrypted by the ransomware.

The Sage virus is similar to other DJVU ransomware variants like Held, Hlas, Qual, and Sarut. This virus encrypts a wide range of common file types and appends its distinct “.sage” extension to all files. For instance, a file named “1.jpg” would be altered to “1.jpg.sage” and “2.png” to “2.png.sage“.

Upon successful encryption, malware spawns a special text file named “_readme.txt” and places it in every folder containing the encrypted files. It also adds the readme file to the desktop, so the victim will not miss the attack even without opening folders.

The image below provides a visual representation of files with the “sage” extension:

Encrypted Files by STOP/DJVU Ransomware

Name	Sage Virus
Ransomware family¹	DJVU/STOP² ransomware
Extension	.sage
Ransomware note	_readme.txt
Ransom	From $499 to $999 (in Bitcoins)
Contact	[email protected], [email protected]
Detection	Trojan:Win32/Tnega!MSR Removal, Win32:Adware-DNA [Adw] Virus Removal, Win32:Secat [Trj] Virus Removal
Symptoms	Encrypted most of your files (photos, videos, documents) and adds a particular “.sage” 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 Vidar Stealer or RedLine Stealer; Manages to install a SmokeLoader backdoor;
Fix Tool	To remove possible malware infections, scan your PC: 6-day free trial available.

This message asking payment is for restore files via decryption key:

_readme.txt (STOP/DJVU Ransomware) – The terrifying alert demanding users to pay off the ransom to decrypt the encoded data contains these exasperating warnings.

Sage ransomware arrives as a set of tasks that are used to perform different functions on a victim’s computer. One of the first ones being launched is winupdate.exe, a tricky process that displays a false Windows update pop-up during the attack. This is meant to convince the victim that a sudden PC slowdown is caused by a Windows update.

Simultaneously, the ransomware runs another process (usually named by four random characters) which initiates scanning the disk for target files and ciphering them. Then the ransomware removes Volume Shadow Copies from the system through the following CMD command:

vssadmin.exe Delete Shadows /All /Quiet

Once erased, it becomes virtually impossible to recover the previous computer state using System Restore Points. The problem is, ransomware operators are getting rid of any built-in Windows techniques that could help the victim to regain files for free. In addition, the rascals modify the Windows HOSTS file by adding a list of domains to it and linking them to the localhost IP. As a result, the victim will witness a DNS_PROBE_FINISHED_NXDOMAIN error when accessing one of the listed websites.

We noticed that ransomware tries to restrict websites that post various how-to guides for computer users. It is clear that by hindering specific domains, the perpetrators are seeking to hinder the victim from reaching relevant and helpful ransomware-attack-related information online. The virus also stores two .txt files on the victim’s computer that present information related to the attack – the victim’s public encryption key and personal ID. These two files are named bowsakkdestx.txt and PersonalID.txt.

After all these alterations, the malware doesn’t halt. Variants of STOP/DJVU are inclined to release Vidar password-stealing Trojan on compromised systems. This threat carries an huge list of capabilities, including:

Manipulating and viewing files on the victim’s computer without their knowledge.
Extracting sensitive information such as browser cookies, saved passwords, and browsing history.
Obtaining unauthorized access to login credentials of Steam, Telegram, and Skype.
Granting the hackers remote control over the victim’s computer for various malicious activities.
Stealing cryptocurrency wallets from the victim’s system.
Gathering sensitive data by running malicious software on the victim’s computer.

The encryption algorithm in STOP/Djvu ransomware is AES-256. So, once your data is encrypted with an online decryption key, the possibility to get your files back without paying the ransom are quite low. Thing is, online key is unique for each victim, and brute forcing it will take too much time.

Retrieving the online key in any other way is also close to impossible. It is stored on a remote server owned by the criminals who promote the Sage infection. For receiving unlocking key the payment should be $999. To get the payment details, the victims should contact the fraudsters 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 pictures, 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.
Do not ask assistants from youtube and recovery data sites for help in recovering your data.
They can use your free decryption quota and scam you.
Our contact is emails in this text document only.
You can get and look video overview decrypt tool:
https://we.tl/t-hPAqznkJKD
Price of private key and decrypt software is $999.
Discount 50% available if you contact us first 72 hours, that's price for you is $499.
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

How To Remove STOP/Djvu Ransomware?

Video Guide

How To Decrypt .sage Files?

How to restore big files?

Try deleting .sage extension on a few big files and opening them. This malware has issues with large files encryption. Either the virus scanned and did not encrypt the file, or it bugged and did not add the filemarker. If you have files that are very large (2GB+), such a situation is highly probable. Please, text me in the comments whether this helped you or not.

The newest extensions released around the end of August 2019 after the criminals made changes. This includes Held, Hlas, Qual etc.

As a outcome of the alterations made by the criminals, STOPDecrypter is no longer supported. It has been 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 configurations, the decryptor will automatically choose the available directories in order to decrypt the currently reachable drives (the connected ones), including the network drives. Extra (optional) locations can be selected with the aid of the “Add” button.

Decryptors usually propose several options considering the specific malware family. The present possible options are shown in the Options tab and can be activated or turned off there. You may locate a detailed list of the currently active Options below.

Click on the “Decrypt” button.

As soon as you add all the desired locations for decryption into the list, click on the “Decrypt” button in order 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 as soon as the decryption procedure is completed. If you need the report for your personal 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 to paste it into emails or messages here if you need to do so.

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

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

Emsisoft does not have a corresponding key in the 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. Your key is unique and is kept on the command server, controlled by criminals. File recovery is only possible through paying the ransom. 🙁

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

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

An offline key was used, though the file recovery operation failed (the offline decryption key isn’t available yet). Nonetheless, this message is a good news for you, because it is possible to restore your files in the future. 🙂

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 .sage Files?

In some case ransomware is not doom for your files…

The Sage ransomware encryption mechanism is next: it encodes every file byte-by-byte, then saves a duplicate, removing (not overriding!) the original file. Hence, the information of the file location on the physical disk is lost, but the original file is not deleted from the drive. The cell, or the sector where this file was stored, can still keep this file, but it is absent in the file system and can be replaced by data that has been loaded to this drive after the deletion. Hence, it is possible to retrieve your files using special software.

I recently had my pc infected by the this 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 glimmer of hope when I went into the subfolders in other folders and found that these files had not been 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, I believe this to be only a small loophole on a backup drive. I’ve since found a further 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 was transferring some files from my backup.

Hopefully, this can help some other people in my situation.

Jamie Newland

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

I have seen Stop/Djvu variants fail to encrypt deeper nested folders, so that you can check that. You may find those are not encrypted.

This ransomware saves encrypted data to a new file, 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 depending on file size and type of data, the not encrypted part may be recoverable.

Joep

Recovering your files with PhotoRec

PhotoRec is an free program, which is originally created for file retrieval from damaged disks, or for file retrieval in case if they are unintentionally deleted. However, with time flow, this program got the ability to retrieve the files of 400 different file types. Hence, it can be used for file recovery after the Sage attack.

First, you need to download this app. It is 100% free, but the developer notifies that there is no assurance that the files will be retrieved. PhotoRec is distributed together with another tool of the same developer – TestDisk. The resulting 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 process is required – the program has all the files it need within the archive, hence, you can fit it on your USB drive, and try to help your friends/parents/anyone who has been attacked by Sage ransomware.

After the start, you will encounter the screen showing you the complete list of your disks. However, this details are probably futile, because the required menu is placed a bit higher. Click this bar, then choose the disk which was attacked by ransomware.

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

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

Finally, you can initiate files retrieval by pressing the “Search” button. You will view the screen where the outcomes of the scan and recovery are shown.

Sage files recovery Video Guide.

Frequently Asked Questions

🤔 How can I open “.sage” files?

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

🤔 This virus has blocked 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 on when new keys or new decryption programs appear.

🤔 What can I do right now?

The Sage 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.

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Brendan Smith