Oonn ransomware, Oonn file virus, .oonn virus: what it is and how to remove it

From our report of Aug 2020 · not reviewed since

More from our earlier report on Oonn ransomware, Oonn file virus, .oonn virus

• In case ransomware corrupted some of the system files, it might cause serious performance issues (crashes, lag, errors, etc.).

From our report of Aug 2020 · not reviewed since

Oonn ransomware - file-encrypting virus that will ask for a ransom in order to get back your data

Oonn ransomware is a data-locking computer infection that targets users all over the world.

First spotted in August 2020, the malware is just another addition to the extensive Djvu ransomware family, which consists of almost 250 variants already. Just as its predecessors such as Nile, Kuus, or Erif, the virus is primarily spread via software cracks and other malicious installers, although it does not mean that other infection means are impossible.

As soon as the Oonn files virus gains access to the machine, it encrypts all personal data (archives, pictures, documents, databases, videos, etc.) on the system and drops _readme.txt ransom note, which serves as a notification from the attackers.

Inside, victims are warned that the only way to remove .oonn file virus extension is to pay a ransom of $490/$980 in bitcoin digital currency. However, there might be other options when it comes to file decryption, so contacting the attackers via helpmanager@mail.ch or restoremanager@airmail.cc is not recommended.

As previously mentioned, Oonn ransomware is mainly spread via contaminated executables that can be downloaded from dangerous sources, such as torrent sites.

Despite this distribution method being primitive as it does not require complex usage of various features (in contrary to exploit kits and similar), threat actors behind the strain are infecting hundreds of users each day, and are releasing new variants on a regular basis. Currently, Djvu is the most prolific crypto-malware that targets home consumers.

As soon as the virus gains access to the device, it first shows a pop-up that looks identical to that of a Windows update prompt. This is done in order to mislead users and prevent them from terminating the encryption process.

This way, the attackers behind the Oonn virus can cause maximum damage to victims and lock the files that are most important to them, including PDF, .jpg, .zip, .doc, .mpg, and many others.

Besides, many ransomware self-delete after the data encryption is complete, although Oonn ransomware removal might still be needed due to several reasons:

Also, Oonn files virus might also prevent access to security-related websites that seek to help victims of ransomware. This is done with the help of the Windows "hosts" file, where a set of URLs is held.

Since the host's file is not malicious and is a part of any Windows system, the security application can not undo such changes, so you should go to the C:\Windows\System32\drivers\etc\ location and delete the file after you remove Oonn ransomware.

• Djvu variants are known to be distributed along with other malware, such as banking trojan AZORult;
• File locking virus might install the data-stealing module into Google Chrome, Mozilla Firefox, MS Edge, or another web browser;
• If not deleted, it might re-encrypt all files that might have been recovered in different ways.

From our report of Aug 2020 · not reviewed since

.OONN virus file recovery options

After malware performs the data locking process, users can no longer access .oonn files anymore.

Instead, they are presented with a ransom note _readme.txt, which provides the following information:

As evident, crooks behind Oonn ransomware virus are willing to provide "test decryption" and even a discount if contact is made within 72 hours of the infection. However, these are all promises that might never be fulfilled, as cybercriminals care little about users' well being, evidently. Thus, if you pay, you might not only lose .oonn files forever but also a significant sum of money.

However, the question remains - how to open .oonn file extension without paying cybercriminals? The answer to this question is not simple, as each case is individual, and consists of many factors.

As a general misconception, users infected with ransomware believe that they can recover .oonn files as soon as they eliminate ransomware from their systems. However, it is important to understand that security software will not allow you to access your locked data, as it is not designed for such a purpose.

Instead, there are several other options that can sometimes be useful when trying to recover Oonn files. Here are a few examples:

• You can attempt to use Emsisoft's decryption tool that might be useful in some cases (i.e., if the virus used an offline ID to lock your files and somebody with the same ID paid criminals and then shared the key with security researchers behind the decryptor);
• Built-in system resources, such as Shadow Volume Copies, might be extremely useful when trying to recover .oonn files. Unfortunately, these backups are deleted by malware if everything goes as planned;
• Third-party recovery solutions can also be used for the data recovery process - they sometimes might help you retrieve at least some portion of lost files.

From our report of Aug 2020 · not reviewed since

First, remove Oonn ransomware and only then attempt to recover .oonn files

What most infected users do not comprehend is that file encryption process and malware infection are two separate functions (although the former is not possible without the latter) and that Oonn virus removal will not allow them to open their lost files.

Nonetheless, it is important to perform various steps in the correct order, or recovered data might be encrypted repeatedly. It is also important to repair affected system files, so malicious functions get fully disabled.

Before you do anything, you should first copy all the encrypted files to another medium - you can choose online could storage such as OneDrive or back it on a physical external drive. Keep in mind that encrypted .oonn files do not have malicious code in them, so they are safe to transfer.

Once that is complete, you can then remove Oonn ransomware from your machine. For that, download and install powerful security software like or , and perform a full system scan. Finally, you can then attempt to recover .oonn files with the help of solutions we provide below.

[GI=method-1]To access Safe Mode with Networking, perform the following actions:

[GI=method-2]System Restore can also sometimes be useful when trying to delete malware:

However, keep in mind that chance of success is relatively low.

Windows Previous Versions Feature might be of use

If. for some reason, malware failed to delete automated Windows backups, and you had System Restore function enabled, you can attempt to retrieve files one-by-one.

In some cases, ShadowExplorer could assist you

ShadowExplorer is another automated tool that could retrieve the locked files if malware failed to delete Shadow Volume Copies.

Try Emsisoft's decryption tool for Djvu

Previous variants of Djvu are known to fail to contact the destination server in order to apply a unique encryption pattern to data. If that happens in your case, you might attempt data recovery with the help of Emsisoft's decryption tool specially designed for the Djvu malware family.