Fantom ransomware virus: what it is and how to remove it
Fantom is a crypto-malware that emerged at the end of summer 2016. In the affected machine it shows fake Configuring critical Windows Updates screen while it encrypts files using a combination of RSA-4096 and AES-256 ciphers.
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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Fantom ransomware virus: summary
| Detection names | No Microsoft detection name is known |
|---|---|
| Ransom note | DECRYPT_YOUR_FILES.HTML |
| Contact | fantomd12@yandex.ru, restorefiles@protonmail.ch, fantom12@techemail.com |
| Encrypted file extension | .fantom |
| 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 10 more facts
| Damage | Not recorded in the old report |
|---|---|
| Name | Fantom ransomware virus |
| Type | File-encrypting ransomware |
| Symptoms | Files renamed with a new extension and a ransom note left in folders |
| Evidence | 8 write-ups by security sites; no sample analysed yet |
| Encrypted files | .fantom |
| Attacker contacts | fantomd12@yandex.ru |
| Free decryptor | No free decryptor is known (checked 6 October 2026) |
| First seen | 24 July 2017 |
| Facts checked | 6 October 2026 |
- File extension:
.fantom - Note file:
DECRYPT_YOUR_FILES.HTML - Contact:
fantomd12@yandex.ru
From our report of Jul 2017 · not reviewed since
More from our earlier report on Fantom ransomware virus
- On March 2017, malware researchers spotted a new version of ransomware.
How Fantom ransomware virus behaves
From our report of Jul 2017 · not reviewed since
Fantom ransomware warns: attention, all files on your computer are encrypted
Fantom is a crypto-malware that emerged at the end of summer 2016.
In the affected machine it shows fake Configuring critical Windows Updates screen while it encrypts files using a combination of RSA-4096 and AES-256 ciphers. Malware has several variants that might append one of these file extensions:
Following data encryption, the virus then leaves DECRYPT_YOUR_FILES.HTML ransom note which starts with a line Attention! All your files have been encrypted. You can stop this unwanted process initiated behind your back with the help of Ctrl + F4 combination.
Different variants of malware might use slightly different ransom-demanding text. However, the main message remains the same - people have to pay the money in order to get back access to their files. Fantom virus might also change the desktop picture with the threatening message:
According to the ransom note, the malware uses encryption systems which can't be cracked. Also, it provides the unique key called ID_KEY to each of its victims and asks them to contact its developers via one of these email addresses:
Unfortunately, crooks are not lying. Fantom ransomware relies on an advanced military-grade encryption system. This system relies on a public encryption key, which is used to encrypt files, and RSA encryption used to protect the first key.
This key is the life saver for those who want to decrypt .fantom file extension files; however, cyber criminals are not willing to give it up for free, so you should not wait for their mercy.
The threat can set a different size of ransom according to the title of the executable. Thus, the cyber criminals gain the chance to earn different sums of profit employing the same executable. For example, if it contains a certain number, let's say, fantomv2.exe, you will be required to pay 2 Bitcoins.
In the case or ransomware attack, we would like to encourage you not to pay the ransom. Files can be retrieved from a backup, but before you plug it into your PC, remove Fantom ransomware first. It helps to clean the system and prevent further possible cyber attacks.
We understand that everyone wants to keep their precious files safe and sound, and that is why we always urge users to create their copies and import them to external devices - in other words, to back them up. Data backups come in handy when the original ones get corrupted, encrypted, or deleted by malware.
Security experts do not advise users to mess with ransomware viruses manually because these malicious programs are designed to hide deeply in the computer system, and they typically consist of many files. The best way to recognize and delete them all is to allow an automatic malware removal tool to do it. Fantom removal can be finished using the .
- .fantom,
- .locked,
- .locked4,
- .11232323.
- fantomd12@yandex.ru,
- restorefiles@protonmail.ch,
- fantom12@techemail.com.
From our report of Jul 2017 · not reviewed since
Quick analysis of malware operation
This ransomware operates in a rather crafty way.
As we have mentioned in the first paragraph, this ransomware manages to deceive a user and pretends to be a Critical Windows Update, asking the victim not to turn off the computer. In the meantime, the ransomware rummages the compromised system, searching for predefined file types.
It scans the computer and encrypts precious memories, work files, and other important documents, leaving no chance to restore and use them. It bypasses essential system files to keep the computer running, creates a ransom note, changes desktop wallpaper, and opens the delback.bat file.
If the victim is not the administrator, a pop-up dialog will show up, asking the victim to make changes on the device. Since this message says that it comes from a verified publisher - Microsoft Windows, inexperienced victims might unknowingly click Yes. This deletes Shadow Volume Copies, which can help you to recover encrypted data.
From our report of Jul 2017 · not reviewed since
Modifications of Fantom ransomware virus
On March 2017, malware researchers spotted a version of ransomware.
The unique feature about this variant of Fantom is that after the infiltration, malware checks computer's location. If it finds out that it ended up in Russia, it discontinues the attack. Otherwise, it starts data encryption procedure and appends a specific file extension based on the timestamp of the contamination event.
One month later, on April 2017, security community started talking about the possibility that Fantom RaaS might show up soon. Researchers find an improvement in ransomware's code that allowed assuming that authors of the ransomware are about to launch RaaS platform. However, it seems that this day hasn't come yet.
However, the same month Fantom ransomware changed its design. Virus researchers have detected a brand new version of this threat. The hackers of this peculiar malware noticed that it contains major improvements in its source code and execution manner. As a result, they lead to alternations in its veneer as well.
In contrast to previous versions, it appends a different file extension. Now all encoded files contain .11232323 file extension. Payment guidelines are also presented in a different file RESTORE-FILES.11232323.hta. Besides this file, it also loads additional two images hxxp://iplogger.ru/1qzM6.gif and hxxp://iplogger.ru/1wzM6.gif to inform about the hijacking process.
Interestingly, that the malware also locates the country of victims' residence. According to the initial report, the malware terminates itself if a victim is Russian. No major changes in its distribution process are reported.
The Fantom ransomware virus ransom note
Attention! All your files have been encrypted.
Due encrypting was used algorithm RSA-4096 and AES-265, used for protection military secrets.
That means RESTORE YOU DATA POSIBLE ONLY BUYING decryption passwords from us.
Getting a decryption of your files is – SIMPLY task.
That all what you need:
1. Send Your ID_KEY on mailbox.
2. For test, decrypt 2 small files, to be sure that we can decrypt you files.
3. Pay for our services.
4. GET software with passwords for decrypt you files.
5. Make measures to prevent this type situations again.
IMPORTANT(1)
Do not try restore files without our help, this is useless, and can destroy you data permanently.
However, the files can be recovered even after the removal of our program and even after reinstalling the operating system.
[...]
How to remove Fantom 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 Fantom 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
Fantom 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 confirm the family
Copy
DECRYPT_YOUR_FILES.HTMLand one or two files ending in.fantomto a USB stick, and leave the originals where they are.From another device, upload the note and a sample file to ID Ransomware or No More Ransom's Crypto Sheriff, which name the family from the note, the extension and the file structure.
Write down the contact address and your personal ID from the note, because a decryptor or the police may ask for them.
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 Fantom 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 Fantom 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 Jul 2017 · not reviewed since
Infiltration methods of the ransomware virus and how to avoid it
Fantom ransomware is distributed via malicious websites, emails, malware-laden ads, and other methods.
There are several methods how the user can protect its computer from ransomware attacks, and the main thing that PC users should know that it is a must be careful while browsing the Internet:
- Avoid clicking on suspicious ads, links or buttons.
- Bypass clicking on ads or articles with click bait titles.
- Never open email attachments that unknown people send to you. No matter if the attachment is named as invoice, resume, phone bill, or similarly, it does not necessarily mean that it is a safe file. Vice versa - crooks tend to name malicious attachments exactly like that because their aim is to make the victim feel safe about the file and open it without even thinking about potential hazards.
- Try to avoid opening files that your computer system identifies as potentially dangerous, and keep a proper anti-malware software installed on your computer.
From our report of Jul 2017 · not reviewed since
The safe way to remove Fantom virus from the system
You have to clean the computer from malicious files completely; otherwise, any malicious files left behind can make your system vulnerable to further ransomware attacks and cause computer malfunctions.
Fantom removal must be completed using a powerful software, such as or , that can remove viruses.
The virus might attempt to stop you from running security programs, so in such cases, follow instructions provided below. They will help to disable the virus and remove Fantom with the help of security software.
[GI=method-1]If your scanner is blocked, try rebooting your computer to Safe Mode with Networking before a full system scan. Once you finish it, you should check your computer when in normal mode as well.
[GI=method-2]If you can't launch your anti-spyware, you can try System Restore method to disable the virus. However, don't forget to remove its files from the system after disabling your virus.
Please, do not support frauds by paying the ransom. Keep in mind that cyber criminals might send you a useless piece of software that cannot help to recover your files. Besides, it can be filled with malicious components allowing crooks to exploit your computer system even more. If you have lost your precious files, try recovering them from a backup or use one of the methods listed below.
It might help you to restore your lost data. We definitely think that it is worth a try since a free and official Fantom decryption tool hasn't been released yet.
Windows Previous Versions feature can help you to restore data
This program helps to retrieve individual files, besides, before you use it, remember that it can help you only in case you have enabled Windows Previous Features feature in your PC.
Fantom 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 Fantom 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 .fantom and no longer open.
Setting it up step by step: 3-2-1 backups on Windows 11 and 10.
Stream videos without limitations, no matter where you are
There are multiple parties that could find out almost anything about you by checking your online activity.
While this is highly unlikely, advertisers and tech companies are constantly tracking you online. The first step to privacy should be a secure browser that focuses on tracker reduction to a minimum.
Even if you employ a secure browser, you will not be able to access websites that are restricted due to local government laws or other reasons. In other words, you may not be able to stream Disney+ or US-based Netflix in some countries. To bypass these restrictions, you can employ a powerful VPN, which provides dedicated servers for torrenting and streaming, not slowing you down in the process.
Data backups are important - recover your lost files
Ransomware is one of the biggest threats to personal data.
Once it is executed on a machine, it launches a sophisticated encryption algorithm that locks all your files, although it does not destroy them. The most common misconception is that anti-malware software can return files to their previous states. This is not true, however, and data remains locked after the malicious payload is deleted.
While regular data backups are the only secure method to recover your files after a ransomware attack, tools such as can also be effective and restore at least some of your lost data.
Questions about Fantom ransomware virus
Is there a decryptor for .fantom files?
That depends on the family behind the .fantom extension, which this guide cannot confirm yet from the reports alone. Check No More Ransom and ID Ransomware with your ransom note and one encrypted file; they list families with free tools.
If none exists today, keep the encrypted files and a copy of the note on a separate drive, because decryptors are sometimes published months later after flaws are found or servers are seized. Never buy a decryptor from a website that is not the security company that made it.
Should I pay the ransom in DECRYPT_YOUR_FILES.HTML?
Not before you have tried everything else. Identify the family from DECRYPT_YOUR_FILES.HTML and one encrypted file, check No More Ransom for a free decryptor, and look for clean copies in OneDrive, backups and Previous Versions.
Paying funds further attacks, may be illegal if the group is sanctioned, and is no promise of a working key: many victims get partial or broken decryption. If you consider paying for business-critical data, involve the police and a professional incident responder first, and never pay through intermediaries who promise their own decryption.
How do I open .fantom files?
You cannot open them by renaming or by choosing another program. The .fantom ending shows that Fantom 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 Fantom ransomware virus. Store the encrypted files on an external disk until then.
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 Fantom ransomware virus get on my computer?
The way Fantom 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 .fantom 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 Fantom ransomware virus steal my files or passwords?
We do not know yet. Nothing published so far shows data theft by Fantom ransomware virus, but the only confirmed sign is files that end in .fantom 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 Fantom 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 delete DECRYPT_YOUR_FILES.HTML?
Yes, the note itself is harmless text and deleting it does not affect your files. Keep at least one copy first, outside the infected PC. DECRYPT_YOUR_FILES.HTML contains your personal ID and the attackers' contact details, which identification services use to tell which family encrypted your files, and which a decryptor may need later.
Police reports also ask for it. Once you have saved a copy, you can remove the notes from every folder after the ransomware program has been removed and your files are restored or backed up.
My files got .fantom overnight. What happened?
Ransomware often runs at night or when the PC is idle, so the encryption finishes before anyone notices. It usually entered earlier through a cracked program, a fake installer, an e-mail attachment or remote desktop with a weak password.
The .fantom extension marks every file it reached. Start by disconnecting the PC from the network, then identify the family from the ransom note and one encrypted file, check for a decryptor, and look for copies in backups and OneDrive before you consider anything else.
Will Fortect remove Fantom 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 Fantom 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
- Wikipedia, the free encyclopedia: RSA (cryptosystem) (read October 6, 2026)
- Wikipedia, the free encyclopedia: Advanced Encryption Standard (read October 6, 2026)
- 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)