HOOP Ransomware

HOOP Ransomware uses the AES-256 encryption algorithm. This STOP/Djvu family is one of the most popular infection!

You may be interested in taking a look at our other antivirus tools: Trojan Killer and Trojan Scanner.

Technical details:

NameHOOP Virus
FamilySTOP/Djvu Ransomware
Note_readme.txt
File Extenstion.hoop
AlgorithmAES-256 encryption. If HOOP cannot establish a connection to crooks server before starting the encryption process, it uses the offline key. This key is the same for all victims(!), making it possible to decrypt .hoop files in the future.
RansomFrom $490 to $980 (in Bitcoins)
Damage
  1. ⮞ Can delete Volume Shadow copies to make victim’s attempts to restore data impossible;
  2. ⮞ Adds a list of domains to HOSTS file to block access to certain security-related sites;
  3. ⮞ Installs password-stealing Trojan on the system, like Azorult Spyware;
DistributionThird-party downloaders, installers, peer-to-peer networks, RDP exploits, etc.,
Other variants
  • Orkf Ransomware (.orkf encrypted files)
  • Iwan Ransomware (.iwan encrypted files)
  • Lqqw Ransomware (.lqqw encrypted files)


  • The HOOP virus can correctly be described as ransomware. This virus encrypts your files and then asks you for the ransom payment to get your files back. HOOP belongs to the STOP/Djvu ransomware family - one of the most active families nowadays. The favorite victims of this malware group are individuals who download the programs from third-party websites.

    In the process of HOOP malware attack, your files are encrypted with the AES-256 algorithm. This cipher means about 2^256 decryption keys - a 78-digit number. Unfortunately, it is likely impossible to get the key with brute force or another popular password hacking method.

    It is essential to mention how HOOP malware is distributed. It was said that the primary source for the whole STOP/Djvu family is dubious sites that are spreading “hacked” software and untrustworthy tools. HOOP is not an exclusion. This ransomware is usually embedded into a spread program as “free”, even though it must be purchased on the official site. Users who crack the license checking in these programs (that allows them to use it for free) add malware in the “final product” because they are paid by virus developers. The same thing is about untrustworthy tools - cheat engines, Windows activators, or keygens. Since all of these programs usually require you to disable the antivirus tool, you will likely detect that something is wrong when it is too late.

    Encryption process

    The HOOP ransomware uses the AES-256 encryption algorithm. That is not the strongest method, but it still provides an overwhelming amount of possible decryption keys. To brute force the 78-digit number of keys, you need 3.5 unvigintillion years (1*10^65), even if you use the most powerful regular PC. Quantum computers can show a bit better results, but it is still too slow to get your files back while you are alive.

    The exact algorithm of encryption is next: malware scans each folder for the files it is able to encrypt. Then, when it finds the target, it makes a copy of your file, removes the original one, encrypts the copy and leaves it instead of the removed original. Such a procedure is done to prevent the situation when you have already opened the file, so ransomware is not able to read it because of the Windows restrictions. To each encrypted copy, the virus adds the specific extension - ".hoop". Then, ransomware creates a _readme.txt file in the folder where the encrypted file is located, and goes to the next folder.

    .HOOP Files

    Such an encryption method can be exploited for file recovery. Since the original file is deleted, you may try to recover it using the file recovery tools. The less time is passed - the bigger the chance to get your files back, so hurry up!

    Another specific moment that can help you to use the files even after the encryption is the fact that HOOP ransomware encrypts only the first 150KB of each file. Hence, you can try to run a big file, such as video or music, without the encryption. Similar feature also works with other ransomware families - Dharma, Conti and Makop encrypt the same 150KB.

    Clop ransomware exploits vulnerability in SolarWinds Serv-U
    Clop ransomware exploits vulnerability in SolarWinds Serv-U

    Ransom note: _readme.txt

    Ransom note is the same for the whole ransomware family. In fact, it is one of the main signs of to which family the certain ransomware belongs. Here is the typical note for STOP/Djvu family:

    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:
    
    hxxps://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:
    
    helpteam@mail.ch
    
    Reserve e-mail address to contact us:
    
    helpmanager@airmail.cc
    
    Your personal ID:
    XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
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