LOOY Virus (.Looy File) Ransomware

The Looy virus, known as a ransomware, is part of the STOP family. This malware family is notorious for its malicious file encryption capabilities. Once the Looy virus infects a computer, it targets various types of files, like documents, videos, photos, and more. It alters the file structure and adds the “.looy” extension to each file, making them unusable without the decryption.

Looy Virus Overview

Looy

🤔 Looy virus is ransomware that belongs to the DJVU/STOP family. Its main target is to lock all of your files it can reach. After that this ransomware asks for a ransom fee – ($499 – $999) in Bitcoin.

The Looy virus is a malware type that encrypts your files and forces you to pay for their decryption. This ransomware ciphers various file types. ciphered files are identifiable by a distinct “.looy” extension. As a result, the files touched by ransomware become inaccessible and unusable.

After that, the ransomware asks for a file decryption payment in Bitcoin from its victims, that ranges from $499 to $999, depending on the time passed after the attack. Typically, a ransom text file is named as “_readme.txt“.

Looy Ransomware works with Salsa20 encryption algorithms to cipher the targeted files. Since Looy virus utilizes such a robust ciphering method, it becomes pretty hard, if even possible, to pick the decryption key without the assistance of the attackers.

Once Looy malware finishes the encryption, it shows a ransom note to the user, demanding a ransom payment for the decryption key. The ransom note provides instructions on how to pay off the bill and often includes threats of data loss or ransom amounts surge if the ransom is not paid within a specified timeframe.

I have compiled an all-encompassing list of potential solutions, advice, and approaches to stop the Looy ransomware and recover your files. In some cases, it may be possible to restore your files, while sometimes, it may be impossible.

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📌 Important Reminder!

It is essential to say that paying off the bill is not a guarantee of the successful recovery of your files. The crooks behind the Looy virus are known for their untrustworthiness. There have been instances where people have paid the ransom, only to be denied by the cybercriminals with the decryption key provision.

Looy uses a unique key for each victim, with one exception:

If Looy fails to establish a connection with its command and control server (C&C Server) before starting the encryption process, it resorts to using offline keys. An offline key is not unique and is the same for all users, which allows for the decryption of files encrypted by the ransomware.

The Looy virus bears resemblance to other DJVU ransomware samples like Kool, Nood, Wiaw, and Wisz. This virus encrypts a wide range of common file types and appends its distinct “.looy” extension to all files. For instance, a file named “1.jpg” would be altered to “1.jpg.looy” and “2.png” to “2.png.looy“.

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

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

Encrypted Files by STOP/DJVU Ransomware

Name	Looy Virus
Ransomware family¹	DJVU/STOP² ransomware
Extension	.looy
Ransomware note	_readme.txt
Ransom	From $499 to $999 (in Bitcoins)
Contact	[email protected], [email protected]
Detection	Trojan:MSIL/Lokibot.PA!MTB Virus Removal, Trojan:MSIL/AsyncRat.NE!MTB Virus Removal, Ransom:MSIL/FileCoder.YG!MTB Virus Removal
Symptoms	Encrypted most of your files (photos, videos, documents) and adds a particular “.looy” 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 frightening notification insisting users to pay off the ransom to decrypt the encoded data contains these exasperating warnings.

Looy ransomware arrives as a set of procedures that are needed to perform different functions on a victim’s computer. One of the primary ones being launched is winupdate.exe, a sneaky process that displays a fraudulent Windows update notification during the attack. This is meant to convince the victim that a sudden system slowdown is caused by a Windows update.

Meanwhile, the ransomware runs another process (usually named by four random characters) which starts scanning the computer for target files and ciphering them. Next, the ransomware removes Volume Shadow Copies from the system by the following CMD command:

vssadmin.exe Delete Shadows /All /Quiet

Once removed, it becomes virtually impossible to restore the previous computer state using System Restore Points. The problem is, ransomware operators are getting rid of any built-in Windows approaches that could assist the victim to recover files for free. In addition, the crooks modify the Windows HOSTS file by appending a list of domains to it and redirecting them to the localhost IP. As a result, the victim will face a DNS_PROBE_FINISHED_NXDOMAIN error when trying to access one of the blacklisted websites.

We’ve observed that ransomware tries to restrict websites that post various how-to guides for computer users. It is evident that by limiting specific domains, the crooks are seeking to hinder the victim from connecting to relevant and helpful ransomware-attack-related information online. This malware also stores two text files on the victim’s computer that offer details related to the attack – the victim’s public key and personal ID. These two files are named bowsakkdestx.txt and PersonalID.txt.

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

Stealing Steam, Telegram, Skype login / password;
Stealing cryptocurrency wallets;
Downloading other 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 perform other tasks on the victim’s computer remotely.

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 are quite low. Thing is, this key is unique for each victim, and brute forcing it will take too much time.

Getting the online key in any other way is also nearly impossible. It is kept on a server owned by the crooks who spread the Looy malware. For receiving unlocking key the payment should be $999. To see the payment details, the victims should contact the hackers 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 .looy Files?

How to restore big files?

Try deleting .looy extension on a few big files and opening them. This malware has issues with large files encryption. Either the virus accessed and did not encode the file, or it failed 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 Kool, Nood, Wiaw etc.

As a result 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. Additional (optional) locations can be selected with the aid of the “Add” button.

Decryptors usually offer several options depending on the specific malware family. The present possible options are shown in the Options tab and can be enabled or deactivated there. You may find 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. Recovery of files without paying the criminals is impossible. 🙁

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

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

Malware used an offline key, but files could not be restored (the offline decryption key isn’t available yet). But, receiving this message is good news for you, since it might be 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

This stands for a DNS issue present in your system. Our first recommendation is to reset your HOSTS file back to default.

How to Restore .looy Files?

In some case ransomware is not doom for your files…

The Looy ransomware encryption algorithm is next: it encrypts every file byte-by-byte, then saves a duplicate, erasing (not overriding!) the initial file. Hence, the data of the file placement on the disk drive is lost, but the original file is not removed from the drive. The cell, or the sector where this file was stored, can still keep this file, but it is not listed by the file system and can be overwritten by data that has been loaded to this disk after the deletion. Hence, it is possible to restore 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 Looy 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 open-source program, which is initially created for file retrieval from damaged disks, or for file retrieval in case if they are unintentionally deleted. However, as time has gone by, this program received the ability to restore the files of 400 different formats. Hence, it can be used for file recovery after the Looy 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 restored. PhotoRec is spread together with other utility of the same developer – TestDisk. The program archive will bear TestDisk name, but don’t worry. PhotoRec files are right inside.

To run PhotoRec, you need to find and open “qphotorec_win.exe” file. No installation is needed – this program has all the files it need within the archive, hence, you can mount it on your USB drive, and try to help your friends/parents/anyone who has been attacked by Looy ransomware.

After the start, you will witness the screen showing you the full list of your disk spaces. However, this details are probably unhelpful, because the required menu is placed a bit higher. Click this menu, then choose the disk which was attacked by ransomware.

After picking the disk, you need to choose the destination folder for the retrieved 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 designate the file formats. This feature is located at the bottom, too. As it was mentioned, PhotoRec can recover the files of about 400 different formats.

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

Looy files recovery Video Guide.

Frequently Asked Questions

🤔 How can I open “.looy” 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 Looy 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