Osno ransomware: what it is and how to remove it
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 to lock up all documents, archives, videos, music, and other files, adding .osnoed extension in the process.
Facts checked October 7, 2026. Removal steps tested on Windows 11 (26H2) and checked against Microsoft's and the browser makers' current documentation. Sections marked as our earlier report are the original text: they describe the threat as it was then and have not been reviewed since. The 2026 status, the removal steps and the questions are current.
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Osno ransomware: summary
| Name | Osno ransomware |
|---|---|
| Also known as | FakeRansomware |
| Type | Ransomware, cypro-virus, file locking virus |
| Related executables | Osno.exe, FallGuysStats.exe, Chrome updaters.exe, CardGame.exe, osno-crypted.exe |
| Malware family | Malware comes as a part of Osno stealer kit, which stems from a known info-stealer strain Babax |
| Extension | Files appended with .osnoed extension, e.g., "picture.jpg" is turned into a "picture.jpg.osnoed" |
| Removal | Scan the PC with security software to find and remove the malware and anything installed with it. Fortect scans Windows for malware and repairs the system files and settings it damaged. Remove it nowTo use the full-featured product, you have to purchase a license for Fortect. The scan is free. |
Show 15 more facts
| Ransom note | None delivered, although a lock screen Osno Decryptor.exe is launch instead; the text of the note is not in our records |
|---|---|
| File recovery | If no backups are available, recovering data is almost impossible. Nonetheless, we suggest you try the alternative methods that could help you in some cases – we list them below |
| Malware removal | Perform a full system scan with powerful anti-malware software |
| Detection names | No Microsoft detection name is known |
| Contact | Not recorded in our earlier report |
| Encrypted file extension | .osnoed |
| Decryptor | No free decryptor is known for this variant; check No More Ransom (nomoreransom.org) for updates |
| Distribution | Not recorded in the old report |
| Damage | Not recorded in the old report |
| Symptoms | Files renamed with a new extension |
| Evidence | 4 write-ups by security sites; details still limited |
| Encrypted files | .osnoed |
| Free decryptor | No free decryptor is known (checked 7 October 2026) |
| First seen | 13 October 2020 |
| Facts checked | 7 October 2026 |
- File extension:
.osnoed
From our report of Oct 2020 · not reviewed since
More from our earlier report on Osno ransomware
- Malware can change the way Windows systems operate, causing errors, crashes, lag, and other stability issues.
How Osno ransomware behaves
From our report of Oct 2020 · not reviewed since
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 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, 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.
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:
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.
- 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.
The Osno ransomware note
We did not record the full text of the ransom note in our report.
How to remove Osno ransomware
Tools you'll need
All of these are free except where noted. Download them on a clean device if the infected PC is offline.
- A USB stick: to keep the ransom note, two or three encrypted files and screenshots off the infected PC.
- Microsoft Defender Offline: built into Windows 11 and Windows 10; scans before Windows starts, so running malware cannot hide.
- Microsoft Safety Scanner: a second, portable scanner with current signatures; each download works for 10 days.
- ID Ransomware: identifies the family from the note and one encrypted file and says whether a decryptor exists.
- No More Ransom: the free decryptors from police and security companies; check it again every few months.
- Fortect (optional): scans Windows for malware and repairs the system files and settings it damaged. The free scan is in the box above.
How to remove Osno ransomware and get your files back
Work in this order.
Disconnecting comes first, removal comes before any restore, and nothing here asks you to contact the attackers.
Step 1: Disconnect the PC and unplug backup drives
Osno ransomware encrypts everything it can reach, including drives and shares you connect later. Cut the network first: cable out, or Wi-Fi off from the taskbar.
Then unplug every USB stick and backup disk and pause cloud sync, so the encrypted versions do not replace your online copies. Do not reconnect any of them until the ransomware is removed from the Windows 11 or Windows 10 PC.
Windows 11: turn off Wi-Fi to take the PC offline. Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 2: Save the ransom note and identify the family
Find the ransom note, usually a
.txt,.htmlor .hta file in every folder or on the desktop, and copy it with one or two encrypted files to a USB stick.From another device, upload them to ID Ransomware or No More Ransom's Crypto Sheriff, which name the family from the note and the file extension. Write down the contact address and your personal ID from the note for the report.
Warning: Never contact the attackers from the infected Windows 11 or Windows 10 PC.
Windows 11: the ransom note and encrypted files to copy for identification. Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 3: Check for a free decryptor
For Osno ransomware, no free decryptor is known (checked 7 October 2026). Search the family name in the No More Ransom decryption tools list and in the free decryptors of Emsisoft, Avast and Kaspersky, because new tools appear years after an attack.
Important: Keep the encrypted files even if nothing works today, and do not pay before every free option is ruled out: payment does not guarantee a working key.
Decryptors run on Windows 11 and Windows 10, but only after the ransomware itself is removed.
Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 4: Remove the ransomware before you restore or decrypt
Restoring or decrypting files while Osno ransomware still runs lets it encrypt them again. Run a Full scan in Windows Security > Virus & threat protection > Scan options, then the Microsoft Defender Antivirus (offline scan).
If the ransomware blocks Windows Security, start Safe Mode with Networking and scan from there. Some families install a password stealer as well, so let both scans finish on Windows 11 or Windows 10.
Windows 11: Windows Security > Virus & threat protection > Scan options. Full procedure with screenshots: Run a Microsoft Defender Offline scan
Step 5: Look for shadow copies of the files
Open Command Prompt as administrator and run
vssadmin list shadows. If it lists copies dated before the attack, right-click a folder with encrypted files in File Explorer, choose Properties > Previous Versions, and open or restore a version from before that date.ShadowExplorer, a free tool, shows the same copies when the tab is empty or hidden. Most current families delete shadow copies, so an empty list is normal, but the check takes two minutes on Windows 11 or Windows 10.
Windows 11: vssadmin list shadows shows whether shadow copies exist. Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 6: Restore the files from a backup or recover deleted originals
Restore from an external backup, File History or OneDrive's version history, choosing a date before the attack. Connect the backup drive only after the scans are clean, or the ransomware encrypts it too.
If there is no backup, file recovery software can sometimes find the deleted originals, because some ransomware writes an encrypted copy and deletes the original file.
Stop writing to the drive and try recovery on Windows 11 or Windows 10 before new files overwrite the space.
Full procedure with screenshots: Recover deleted files (Recycle Bin, backups, OneDrive) On uGetFix
Instructions for each browser and system
The detailed steps for every browser and system this guide covers. Open the one you use.
Manual removal using Safe Mode
Important! →
Manual removal guide might be too complicated for regular computer users. It requires advanced IT knowledge to be performed correctly (if vital system files are removed or damaged, it might result in full Windows compromise), and it also might take hours to complete. Therefore, we highly advise using the automatic method provided above instead.
Step 1. Access Safe Mode with Networking
Manual malware removal should be best performed in the Safe Mode environment.
Windows 7 / Vista / XP
- Click Start > Shutdown > Restart > OK.
- When your computer becomes active, start pressing F8 button (if that does not work, try F2, F12, Del, etc. - it all depends on your motherboard model) multiple times until you see the Advanced Boot Options window.
- Select Safe Mode with Networking from the list.
Windows 10 / Windows 8
- Right-click on Start button and select Settings.
- Scroll down to pick Update & Security.
- On the left side of the window, pick Recovery.
- Now scroll down to find Advanced Startup section.
- Click Restart now.
- Select Troubleshoot.
- Go to Advanced options.
- Select Startup Settings.
- Press Restart.
- Now press 5 or click 5) Enable Safe Mode with Networking.
Step 2. Shut down suspicious processes
Windows Task Manager is a useful tool that shows all the processes running in the background. If malware is running a process, you need to shut it down:
- Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
- Click on More details.
- Scroll down to Background processes section, and look for anything suspicious.
- Right-click and select Open file location.
- Go back to the process, right-click and pick End Task.
- Delete the contents of the malicious folder.
Step 3. Check program Startup
- Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
- Go to Startup tab.
- Right-click on the suspicious program and pick Disable.
Step 4. Delete virus files
Malware-related files can be found in various places within your computer. Here are instructions that could help you find them:
- Type in Disk Cleanup in Windows search and press Enter.
- Select the drive you want to clean (C: is your main drive by default and is likely to be the one that has malicious files in).
- Scroll through the Files to delete list and select the following:
Temporary Internet Files
Downloads
Recycle Bin
Temporary files - Pick Clean up system files.
- You can also look for other malicious files hidden in the following folders (type these entries in Windows Search and press Enter):
%AppData%
%LocalAppData%
%ProgramData%
%WinDir%
After you are finished, reboot the PC in normal mode.
From our report of Oct 2020 · not reviewed since
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.
From our report of Oct 2020 · not reviewed since
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 recommend using security tools such as or .
Additionally, 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.
[GI=method-1]If you are unable to initiate a scan with security software, access Safe Mode with Networking as explained below:
[GI=method-2]System Restore can sometimes be useful when trying to delete malware from the system:
Data recovery tools might sometimes be able to find unaffected file copies within your hard drive.
Windows Previous Version feature might sometimes be helpful
You might be able to restore files one-by-one if you had System Restore enabled before malware managed to access your device.
ShadowExplorer could be the answer
If the Osno virus failed to delete Shadow Volume Copies, ShadowExplorer should be able to recover all your data without difficulties.
No decryption tool is currently available
Report it and recover your files
Report it
Report the attack even if you do not expect the files back: insurers and banks ask for the report number, and police use the contacts in the note to link cases.
- United States
- FBI IC3 · FTC ReportFraud
- United Kingdom
- Report Fraud (formerly Action Fraud) · NCSC
- Australia
- ReportCyber (ASD)
- EU countries
- Europol: national reporting sites
Give the victim ID, the note and the date the files were encrypted. A business that holds personal data may also have to notify its data protection authority, in the EU within 72 hours.
Make the next attack harmless
Osno ransomware could only hurt the files that had no second copy, and the signs (files that end in .osnoed and no longer open) showed exactly which ones those were.
The 3-2-1 rule fixes that:
- three copies
- two media
- one disconnected
A practical version for a home PC: OneDrive or another cloud backup with version history, plus an external disk that you plug in once a week for File History and then unplug. Test a restore now and then by opening a few files from the backup on another device.
Details, schedules and what not to back up are in our 3-2-1 backup guide for Windows.
Do not let government spy on you
The government has many issues in regards to tracking users' data and spying on citizens, so you should take this into consideration and learn more about shady information gathering practices.
Avoid any unwanted government tracking or spying by going totally anonymous on the internet.
You can choose a different location when you go online and access any material you want without particular content restrictions. You can easily enjoy internet connection without any risks of being hacked by using VPN.
Control the information that can be accessed by government any other unwanted party and surf online without being spied on. Even if you are not involved in illegal activities or trust your selection of services, platforms, be suspicious for your own security and take precautionary measures by using the VPN service.
Backup files for the later use, in case of the malware attack
Computer users can suffer from data losses due to cyber infections or their own faulty doings.
Ransomware can encrypt and hold files hostage, while unforeseen power cuts might cause a loss of important documents. If you have proper up-to-date backups, you can easily recover after such an incident and get back to work. It is also equally important to update backups on a regular basis so that the newest information remains intact - you can set this process to be performed automatically.
When you have the previous version of every important document or project you can avoid frustration and breakdowns. It comes in handy when malware strikes out of nowhere. Use for the data restoration process.
Questions about Osno ransomware
How do I open .osnoed files?
You cannot open them by renaming or by choosing another program. The .osnoed ending shows that Osno ransomware encrypted the content, and only the matching key can reverse it. Renaming a file back to .docx or .jpg changes nothing except the icon, and it can confuse a future decryptor, so leave the names as they are.
To get the content back, use a backup, an unencrypted copy elsewhere, or a decryptor listed on No More Ransom if one exists for Osno ransomware. Store the encrypted files on an external disk until then.
When will a decryptor for Osno ransomware be released?
Nobody can promise a date. When we last checked, on 7 October 2026, no free decryptor is known. Decryptors usually appear after one of three events:
- police seize the attackers' servers and keys
- the authors leak or publish the master keys
- researchers find a mistake in how the ransomware generates keys
Some families got a tool within weeks, others never. Keep the encrypted files and the note on an external drive, check No More Ransom every few months, and follow news about the Osno ransomware family. A decryptor may need an original file, so keep any unencrypted copies too.
Should I pay the ransom?
We advise against it, and so do the FBI, Europol and national cyber agencies. Payment does not guarantee a working tool: some attackers never reply, some tools damage files, and some variants have no decryptor at all. Paying also funds further attacks and can make you a target again.
Before considering payment, try every recovery option in this guide and report the attack. Companies must involve their legal adviser and insurer, because payments to sanctioned groups can be illegal. If files are truly irreplaceable, store the encrypted copies and wait; decryptors sometimes appear later.
Can a data-recovery company decrypt my files for a fee?
Only if a decryptor already exists or the company pays the attackers for you. Some "ransomware recovery" services advertise that they can decrypt families with no known flaw; in practice they negotiate with the attackers and add their own fee. Others use the same free tools listed on No More Ransom.
Before you hire anyone, ask in writing how they will recover the files, whether they will contact the attackers and what happens if they fail. A legitimate service answers clearly. If a free decryptor exists for your family, you can run it yourself.
How did Osno ransomware get on my computer?
The way Osno ransomware spreads has not been documented yet, so look at your own recent activity. On home PCs, ransomware most often comes with cracked programs, game cheats, key generators and fake updates, or with an e-mail attachment that was opened. On business networks, attackers usually log in through Remote Desktop with a stolen or guessed password.
Think back to what was downloaded or installed in the days before files that end in .osnoed and no longer open, and check the Downloads folder and Installed apps sorted by date. Keep anything suspicious for your report, but do not run it again.
Did Osno ransomware steal my files or passwords?
We do not know yet. Nothing published so far shows data theft by Osno ransomware, but the only confirmed sign is files that end in .osnoed and no longer open, which says nothing about what happened before. Many current ransomware attacks copy files or run a password stealer first, so it is wise to act as if they did.
From a clean device, change the passwords that were saved in the browsers on this PC, starting with e-mail and banking, sign out of all sessions and turn on two-step verification. Watch bank statements and account activity for the next few weeks.
Is Osno ransomware the same as other ransomware with a similar name?
Not necessarily. Ransomware names come from the file extension, the note or a word in the code, so unrelated families often end up with similar names, and one family can appear under several names. The difference matters: a decryptor or advice for one family does not fit another and can damage files.
Compare the ending added to your files and the exact name of the note with the summary table at the top of this guide, then upload the note and one encrypted file to ID Ransomware from a clean device. If the result names another family, follow the guide for that family instead.
Can I just remove .osnoed from the file names?
You can try it on a copy, but for real ransomware it will not help. The .osnoed extension is only a label; the file content has been scrambled with a key the attackers hold.
If a renamed copy opens normally, the malware only renamed files, which happens with some fake ransomware, and you can rename the rest back. If it does not open, leave the files as they are. Renaming encrypted files can confuse a decryptor later, so always work on copies.
Should I reinstall Windows after the .osnoed attack?
Reinstalling removes the ransomware but not the encryption: your files ending in .osnoed stay encrypted afterwards. So first copy the encrypted files and the ransom note to a separate drive, in case a decryptor appears later. Then decide:
- a clean-up with an offline scan is often enough for home PCs
- while a full reset is safer if remote access was involved
- scans keep finding new items
Restore your backups only after the PC is clean, and change passwords from another device.
Will Fortect remove Osno ransomware?
Fortect scans Windows for malware and unwanted programs and repairs the system files and settings they change, and its free scan shows what it finds on your PC before you decide anything.
For Osno ransomware, follow the plan above as well: the browser steps take back permissions and settings that no scanner treats as a threat, and uninstalling the program that brought it removes the source.
Run Microsoft Defender's full scan and, if anything was found, its offline scan as a second opinion. If the symptoms are gone after the plan and both scans are clean, there is nothing more to do.
Sources
- Proofpoint: Encryption (read October 7, 2026)
- Wikipedia: Exploit (computer security) (read October 7, 2026)
- Dieviren: Dieviren (read October 7, 2026)
- CISA: StopRansomware (read October 7, 2026)
- No More Ransom (read October 7, 2026)