How to remove Osno ransomware

Osno ransomware is a crypto-virus that uses familiar executable names to spread

Osno ransomware is a type of malware that is designed to extort money from innocent victims, although it can also function as an info-stealing virus. Once inside a Windows computer, it employs an encryption algorithm^[1] to lock up all documents, archives, videos, music, and other files, adding .osnoed extension in the process. Suchlike modified files can no longer be accessed by victims, as they require a unique key held hostage by the attackers.

Unlike many other malicious programs of this type, the Osno file virus does not deliver a text-based ransom note after the encryption. Instead, a file called Osno Decryptor.exe is launched – it is presented as a lock screen and only includes a 24-hour timer and a field where the decryption code is meant to be entered. However, the attackers do not provide contact information, ransom size, or any other relevant information. Nonetheless, you could attempt to recover .osnoed files with the help of alternative methods we provide below.

This ransomware is a type of malware that attacks the Windows system exclusively and comes from a well-known malware kit known as Osno stealer. Therefore, those who have their files locked by this malware are highly likely to have additional modules or malicious components installed. Thus, it is important to remove Osno ransomware as soon as it manages to access the targeted computer.

As a general rule, malicious actors who buy access to the malware kit can use various distribution techniques, including spam emails, exploits,^[2] vulnerabilities, botnets, fake updates, and much more. Nonetheless, it was spotted being delivered using well-known names of legitimate applications and companies to deceive users and make them double-click the malicious file (e.g., FallGuysStats.exe, Chrome updaters.exe), which begins the infection routine.

While visually, the infection process seems instantaneous, the virus performs a variety of changes to the operating system in the background (since these changes might be difficult to revert after Osno ransomware removal, we recommend using FortectIntego as an automatic solution – it should be able to repair all the damaged system files). For example:

• performs a variety of checks for a smooth installation;
• modifies Windows registry to establish persistence;
• deletes Shadow Copies to prevent quick data recovery;
• drops hundreds of malicious files and establishes new processes, etc.

After that, the encryption process begins, and the Osno virus locks all personal videos, documents, databases, and other files. The malware then delivers a pop-up window that locks the screen, which includes a brief message:

idfk

24:00:00

Enter decryption code below:

As evident, the field is meant to be used to enter the decryption key. In other cases, malware authors typically provide contact details with instructions on how to transfer the payment to a particular bitcoin wallet. As evident, since no email or other contact details are provided, retrieving a key from the attackers for .osnoed files is currently impossible.

Nonetheless, keep in mind that many threat actors can purchase access to the Osno kit, so more appropriate functions might be added. At present, there is no way to recover the locked data with the help of cybercriminals' decryption tool.

Ways to recover .osnoed files

Ransomware infection can be particular devastating, as the encryption algorithm it applies to personal files is usually secure. Unfortunately, many victims believe that they can remove .osnoed extension by simply deleting malware infection from their systems – this could not be further from the truth.

In order to encrypt data on a Windows machine, ransomware need to infect it first. However, this process is not reversible, as once the data is locked, removing malware with security software will not return files to their previous state. Therefore, do not be surprised that .osnoed extension remains after you perform a full system scan with anti-malware software.

The easiest way to recover .osnoed files is by using backups. These data copies should be prepared before malware manages to break into the machine. Unfortunately, not many users practice adequate data backup procedures and end up losing their files permanently once ransomware manages to break in.

If you had no backups, recovering .osnoed files is quite difficult. If malware failed to perform some of its functions during the infection routine, third-party recovery tools or Windows built-in backups might sometimes be enough to recover some or all of the locked data.

Remove Osno ransomware before attempting data recovery

Since the Osno virus is a relatively new release of malware, there are distinct rules on how the encryption or other process is performed. As mentioned above, hackers can purchase access to malware on underground forums and modify it as they please. Therefore, before you remove Osno ransomware, you should backup all the encrypted files (if you have no working backups).

After that, you can proceed with Osno ransomware removal. While malicious file elimination can be performed manually, it is not something that regular PC users should attempt. Instead, experts^[3] recommend using security tools such as SpyHunterCombo Cleaner or MalwarebytesMalwarebytes. Additionally, FortectIntego can be used to remediate damaged Windows system files and databases. Note that in some cases, you should access Safe Mode with Networking to avoid malware tampering with anti-virus tools. 

For data decryption, please check the instructions we provide below, although keep in mind that the success rate is relatively low. For future reference, ensure that you always backup your most important files on a separate medium.