Ygvb Virus

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Lynne Pruskowski

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Aug 5, 2024, 12:44:29 PM8/5/24
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Ygvbis a piece of malicious software classified as ransomware. Our researchers found this program while inspecting new submissions to VirusTotal, and determined that it belongs to the Djvu ransomware family.

The ransom note informs victims that their files have been encrypted. The only way to restore them is to purchase the decryption keys and software from the attackers. The price of the recovery tools is stated to be 980 USD, and if victims establish contact with the cyber criminals within 72 hours - the ransom will be halved (490 USD). Additionally, the message mentions that decryption can be tested by sending the attackers a single encrypted file.


To prevent Ygvb ransomware from further encryptions, it must be eliminated from the operating system. However, removal will not restore already affected files. The sole solution is recovering them from a backup, if one was created beforehand and is stored elsewhere.


Nuhb, Stopfiles, and OnlyFans are just a few examples of the ransomware we have analyzed. The malware operates practically identically throughout, but these programs do have two significant differences in-between - the cryptographic algorithms they use (symmetric or asymmetric) and the ransom size.


Malware (ransomware included) is proliferated using phishing and social engineering tactics. Malicious programs are typically presented as or bundled with ordinary content. Infectious files can be in various formats, e.g., archives, executables, PDF and Microsoft Office documents, JavaScript, etc. Once such a file is opened - the infection process is jumpstarted.


The most common malware distribution methods include: malicious attachments/links in spam emails and messages, untrustworthy download sources (e.g., unofficial and freeware sites, Peer-to-Peer sharing networks, etc.), drive-by (stealthy and deceptive) downloads, illegal software activation tools ("cracks"), fake updates, and online scams.


Another recommendation is exercising caution with incoming mail. The attachments and links present in suspicious and irrelevant emails/messages - must not be opened, as doing so may result in a system infection.


It is paramount to have a dependable anti-virus installed and updated. This software must be used to run regular system scans and to remove detected threats/issues. If your computer is already infected with Ygvb, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate this ransomware.




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.

You can get and look video overview decrypt tool:


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.


Therefore, some victims were able to decrypt data using a tool developed by cyber security researcher, Michael Gillespie, however, since the encryption mechanism has been slightly changed (hence the new version, released in August, 2019), the decrypter no longer works and it is not supported anymore.


If your data has been encrypted by an older version, you might be able to restore it with the another tool developed by Emsisoft and Michael Gillespie. It supports a total of 148 Djvu's variants and you can find more information, as well as download link and decryption instructions in Emsisoft's official page.


Additionally, Emsisoft is now providing a service that allows to decrypt data (again, only if it was encrypted by Djvu variants released before August, 2019) for those victims who have a pair of the same file before and after the encryption. All victims have to do is upload a pair of original and encrypted file to Emsisoft's Djvu decryption page and download the aforementioned decryption tool (the download link will be provided after uploading files).


Note that the file processing may take some time so be patient. It is also worth mentioning that the system must have an Internet connection during the entire decryption process, otherwise it will fail.


Some victims state that they've successfully restored a part of encrypted data using PhotoRec tool developed by CGSecurity (Christophe Grenier). You can download this tool from CGSecurity's official website.


Now it is worth noting that Djvu ransomware does not encrypt the entire file. Instead, it encrypts only a portion (start) of the file, thereby making it unusable. Luckily, in some cases it is possible to restore other part of the file, which is not encrypted. This is useful when it comes to audio/video files, because even though the start won't be restored, you'll still be able to use most of it.


To restore audio/video data we advise you to use Media_Repair tool developed by DiskTuna. This tool is extremely simple and completely free. You can find the user manual as well as download the tool directly from DiskTuna's website.


G DATA company has also released a "vaccine" capable of preventing Djvu ransomware from encrypting data. This does not mean that the malware won't be able to enter the system or to perform other actions (e.g., change system settings). However, the encryption will be prevented nevertheless. You can download the vaccination tool from this GitHub page.


If you are a victim of a ransomware attack we recommend reporting this incident to authorities. By providing information to law enforcement agencies you will help track cybercrime and potentially assist in the prosecution of the attackers. Here's a list of authorities where you should report a ransomware attack. For the complete list of local cybersecurity centers and information on why you should report ransomware attacks, read this article.


Some ransomware-type infections are designed to encrypt files within external storage devices, infect them, and even spread throughout the entire local network. For this reason, it is very important to isolate the infected device (computer) as soon as possible.


The easiest way to disconnect a computer from the internet is to unplug the Ethernet cable from the motherboard, however, some devices are connected via a wireless network and for some users (especially those who are not particularly tech-savvy), disconnecting cables may seem troublesome. Therefore, you can also disconnect the system manually via Control Panel:


Right-click on each connection point and select "Disable". Once disabled, the system will no longer be connected to the internet. To re-enable the connection points, simply right-click again and select "Enable".


As mentioned above, ransomware might encrypt data and infiltrate all storage devices that are connected to the computer. For this reason, all external storage devices (flash drives, portable hard drives, etc.) should be disconnected immediately, however, we strongly advise you to eject each device before disconnecting to prevent data corruption:


Some ransomware-type might be able to hijack software that handles data stored within "the Cloud". Therefore, the data could be corrupted/encrypted. For this reason, you should log-out of all cloud storage accounts within browsers and other related software. You should also consider temporarily uninstalling the cloud-management software until the infection is completely removed.


This, however, is rare. In most cases, ransomware infections deliver more direct messages simply stating that data is encrypted and that victims must pay some sort of ransom. Note that ransomware-type infections typically generate messages with different file names (for example, "_readme.txt", "READ-ME.txt", "DECRYPTION_INSTRUCTIONS.txt", "DECRYPT_FILES.html", etc.). Therefore, using the name of a ransom message may seem like a good way to identify the infection. The problem is that most of these names are generic and some infections use the same names, even though the delivered messages are different and the infections themselves are unrelated. Therefore, using the message filename alone can be ineffective and even lead to permanent data loss (for example, by attempting to decrypt data using tools designed for different ransomware infections, users are likely to end up permanently damaging files and decryption will no longer be possible even with the correct tool).


Another way to identify a ransomware infection is to check the file extension, which is appended to each encrypted file. Ransomware infections are often named by the extensions they append (see files encrypted by Qewe ransomware below).


One of the easiest and quickest ways to identify a ransomware infection is to use the ID Ransomware website. This service supports most existing ransomware infections. Victims simply upload a ransom message and/or one encrypted file (we advise you to upload both if possible).


The ransomware will be identified within seconds and you will be provided with various details, such as the name of the malware family to which the infection belongs, whether it is decryptable, and so on.


If your data happens to be encrypted by ransomware that is not supported by ID Ransomware, you can always try searching the internet by using certain keywords (for example, a ransom message title, file extension, provided contact emails, crypto wallet addresses, etc.).


Encryption algorithms used by most ransomware-type infections are extremely sophisticated and, if the encryption is performed properly, only the developer is capable of restoring data. This is because decryption requires a specific key, which is generated during the encryption. Restoring data without the key is impossible. In most cases, cybercriminals store keys on a remote server, rather than using the infected machine as a host. Dharma (CrySis), Phobos, and other families of high-end ransomware infections are virtually flawless, and thus restoring data encrypted without the developers' involvement is simply impossible. Despite this, there are dozens of ransomware-type infections that are poorly developed and contain a number of flaws (for example, the use of identical encryption/decryption keys for each victim, keys stored locally, etc.). Therefore, always check for available decryption tools for any ransomware that infiltrates your computer.

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