Thor ransomware virus: what it is and how to remove it
Thor ransomware is cypto-type malware which hails from an infamous family of Locky ransomware. Together with this threat, security researchers discovered Perl ransomware, .Shit file extension virus and Odin virus.
Facts checked October 6, 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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Thor ransomware virus: summary
| Detection names | No Microsoft detection name is known |
|---|---|
| Ransom note | Not recorded in our earlier report |
| Contact | Not recorded in our earlier report |
| Encrypted file extension | .thor |
| Decryptor | No free decryptor is known for this variant; check No More Ransom (nomoreransom.org) for updates |
| Distribution | Not recorded in the old report |
| 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 9 more facts
| Damage | Not recorded in the old report |
|---|---|
| Name | Thor ransomware virus |
| Type | File-encrypting ransomware |
| Symptoms | Files renamed with a new extension |
| Evidence | One write-up by a security site; details still limited |
| Encrypted files | .thor |
| Free decryptor | No free decryptor is known (checked 6 October 2026) |
| First seen | 10 November 2016 |
| Facts checked | 6 October 2026 |
- File extension:
.thor
From our report of Nov 2016 · not reviewed since
More from our earlier report on Thor ransomware virus
- All of your files are encrypted with RSA-2048 and AES-128 ciphers.
- More information about the RSA and AES can be found here: https://en.wikipedia.org/wiki/RSA_(cryptosystem) https://en.wikipedia.org/wiki/Advanced_Encryption_Standard Decrypting of your files is only possible with the private key and decrypt program, All which is on our secret server.
- To receive your private key follow one of the links: 1.http://....
- If all of this addresses are not available, follow these steps: 1.
- After a successful installation, run the browser and wait for initialization.
- Type in the address bar: 4.
- Follow the instructions on the site.
- Your personal identification ID: !!!
How Thor ransomware virus behaves
From our report of Nov 2016 · not reviewed since
Infiltration techniques used by this ransomware
Each version of Locky virus uses quite similar methods to infiltrate victim's computers.
Some of them are delivered via malicious emails, others infect target computers with the help of exploit kits, and others spread via malware-laden ads. Thor ransomware typically arrives in a form of .vbs, .dll, .zip, .js, .hta or .doc file, and can be executed unwillingly. It is not surprising, considering that such files do not look suspicious at all.
Unfortunately, unprotected computers cannot fight against ransomware attack, so they get infected. As we have mentioned before, there is no way to revert damage that ransomware viruses do, unless the victim has data backup stored on an external storage device. To protect your files, you can use external hard drives, USB sticks and similar solutions.
If you want to use online back up solutions, such as cloud services, make sure they are disconnected all the time to protect your data from the entire loss. In case of infiltration, make sure you remove Thor virus from your computer and then use your backup to restore encrypted files.
From our report of Nov 2016 · not reviewed since
Update on Thor file virus distribution
According to the latest reports, Thor virus spreads as a misleading email message titled as Budget or Budget forecast.
It has Zip attachment added to it which seems like an excel file with the budget-themed name. Later, you can see that the attachment is, in fact, the .vbs file that seeks to infect you with Thor ransomware or other versions of Locky. The body of the message asks you to double check the file added to it.
However, you should be careful with such emails, especially if they come from people you are not familiar with. Besides, we should warn you about the latest scam used to promote Locky ransomware several days ago because there is a huge chance that scammers will start using it for the distribution of Thor malware.
In this case, they are trying to trick their victims into believing that the alleged U.S. Office of Personnel Management (OPM) account manager detected illegal operations in their bank account. However, after looking closer at this message it seems obvious that it is filled with grammar or typo mistakes.
Please, make sure you contact your bank and its representatives before clicking the infected file added to such message. If you can see this warning on your computer's desktop, you are infected. In this case, please, proceed to Thor removal process:
From our report of Nov 2016 · not reviewed since
How dangerous is Thor file virus?
Thor ransomware is cypto-type malware which hails from an infamous family of Locky ransomware.
Together with this threat, security researchers discovered Perl ransomware, .Shit file extension virus and Odin virus. Thor is not just an ordinary member of this group of viruses because it can encrypt files with over 400 different file extensions.
To make victim's files useless, it uses a combination of RSA and AES ciphers that distort the structure of every file and scramble the filename by adding .thor file extension to them. As a result, you can easily notice the fact that your computer is hijacked by this ransomware.
Of course, the affected files are not available for a free use - to start using them again you are required to pay a ransom of 0.5 bitcoin. This version of Thor virus uses two files to "inform" its victim about the encryption of his or hers files and a need to pay a special payment. Documents that are supposed to reveal that are presented as _WHAT_is.html and _WHAT_is.bmp.
What is even worse is that this virus is programmed to continue the scan of the system. Once it discovers new files added to it, it initiates another encryption process, so there is no doubt that you must initiate Thor removal on your computer as soon as you find one of its encrypted files. For that, use .
The aim of Thor ransomware is to make files inaccessible and force the victim to pay the ransom. This virus asks for approximately 0.50 Bitcoin to set victim's files free, and this sum equals to 330 US dollars. The ransom notes that Thor virus leaves on the compromised system explain to the victim how to download Tor browser, which is needed in order to access the ransom payment site.
The payment site asks to enter the personal ID, which is presented in the ransom note or to enter any encrypted file name. If your files have been compromised by this ransomware, you have two options - send your money to cyber criminals and wait until they provide the decryption software (unlikely to happen) or remove Thor virus using the anti-malware tool and restore your files from a backup.
If you do not have a backup, we are afraid that there is no way to restore corrupted data, but you can still try some of the data recovery techniques described below this post.
How to remove Thor ransomware virus
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 Thor ransomware virus 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
Thor ransomware virus 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 Thor ransomware virus, no free decryptor is known (checked 6 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 Thor ransomware virus 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 Nov 2016 · not reviewed since
Removal methods of Thor virus
If your PC is already infected with this ransomware, you must remove Thor virus entirely because it can try to encrypt your newest files and files that are kept on the network. To do that, you should use reliable anti-malware tool after updating. If you do not have any security software on your computer, you should choose one of those that are given below.
To restore your files without a backup, we highly recommend following "Data recovery" steps that are provided below the Thor removal steps. Please, do NOT think about paying the ransom because that's how you can lead yourself to the risk of losing your files AND the money. Keep in mind that people who you are dealing with are hackers. They will do anything to increase their income.
To recover your files after infiltration of Thor virus, you can use a special data recovery program. To recover infected files, follow the steps provided below and see how they work:
Use Windows Previous Versions feature to restore files affected by Thor ransomware
If System Restore function was enabled on your computer, you can try Windows Previous Versions feature. For using this option to recover your encrypted files, follow these steps:
Thor decrypter is not available yet
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.
Backups: the 3-2-1 rule
Keep three copies of files that matter, on two kinds of storage, with one copy offline or off-site.
A disk that stays plugged in is reached by malware like Thor ransomware virus together with the PC; one you connect only for the backup is not.
On Windows 11, File History keeps versions on an external drive, and OneDrive keeps earlier versions of synced files. Before restoring anything, make sure the PC no longer shows files that end in .thor and no longer open.
Setting it up step by step: 3-2-1 backups on Windows 11 and 10.
Protect your privacy - employ a VPN
There are several ways how to make your online time more private - you can access an incognito tab.
However, there is no secret that even in this mode, you are tracked for advertising purposes. There is a way to add an extra layer of protection and create a completely anonymous web browsing practice with the help of VPN. This software reroutes traffic through different servers, thus leaving your IP address and geolocation in disguise.
Besides, it is based on a strict no-log policy, meaning that no data will be recorded, leaked, and available for both first and third parties. The combination of a secure web browser and VPN will let you browse the Internet without a feeling of being spied or targeted by criminals.
No backups? No problem. Use a data recovery tool
If you wonder how data loss can occur, you should not look any further for answers - human errors, malware attacks, hardware failures, power cuts, natural disasters, or even simple negligence.
In some cases, lost files are extremely important, and many straight out panic when such an unfortunate course of events happen. Due to this, you should always ensure that you prepare proper data backups on a regular basis.
If you were caught by surprise and did not have any backups to restore your files from, not everything is lost. is one of the leading file recovery solutions you can find on the market - it is likely to restore even lost emails or data located on an external device.
Questions about Thor ransomware virus
How do I open .thor files?
You cannot open them by renaming or by choosing another program. The .thor ending shows that Thor ransomware virus 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 Thor ransomware virus. Store the encrypted files on an external disk until then.
When will a decryptor for Thor ransomware virus be released?
Nobody can promise a date. When we last checked, on 6 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 Thor ransomware virus family. A decryptor may need an original file, so keep any unencrypted copies too.
How did Thor ransomware virus get on my computer?
The way Thor ransomware virus 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 .thor 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.
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.
Did Thor ransomware virus steal my files or passwords?
We do not know yet. Nothing published so far shows data theft by Thor ransomware virus, but the only confirmed sign is files that end in .thor 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 Thor ransomware virus 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 .thor from the file names?
You can try it on a copy, but for real ransomware it will not help. The .thor 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.
Will .thor spread to my other drives?
It can. Ransomware encrypts every drive and network share it can reach while it runs, so external disks, USB sticks and shared folders connected during the attack may also have files ending in .thor. Disconnect everything now, then check each device from a clean computer.
Do not plug a backup drive into the infected PC until the ransomware has been removed with an offline scan. Cloud folders such as OneDrive sync the encrypted versions, but they keep earlier versions you can usually restore.
Will Fortect remove Thor ransomware virus?
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 Thor ransomware virus, 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
- CISA: StopRansomware (read October 6, 2026)
- No More Ransom (read October 6, 2026)
- FTC: How to recognize, remove and avoid malware (read October 6, 2026)
- Microsoft Learn: Microsoft Defender Offline (read October 6, 2026)
- Microsoft Learn: How Microsoft names malware (read October 6, 2026)