DecYourData ransomware: what it is and how to remove it
DecYourData ransomware is a crypto-malware that was first spotted in December 2019, with a variant appearing a month later. Just as many other similar viruses of such type, it relies on file encryption process (which is performed with the help of AES cipher) to hold all personal files like pictures, documents, databases, videos, PDF, and others, hostage, and demand ransom payment in Bitcoin cryptocurrency for DecYourData ransomware decryption software.
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.
Automatic
Get a free scan and check if your PC is infected.
Fortect finds malware, unwanted programs and the Windows damage they leave behind, and repairs it in one pass.
Make sure nothing will rename more files to .dat: an automatic scan checks the PC first.
Do it yourself · free Remove DecYourData ransomware yourself 6 steps, about 18 minutes, no software needed.
Start the steps
DecYourData ransomware: summary
| Name | DecYourData ransomware |
|---|---|
| Type | File locking virus, cryptomalware |
| Encryption algorithm | All files are locked with the help of a symmetric AES encryption algorithm |
| Extension | There is no dot after the full name of the file – instead, the malware uses a space. Each of the encrypted files is appended with a particular template that consists of victim's ID and contact email; an example of an encrypted file: AfaqyStoreDataSource.xss id-42L1AP5921PZ [decyourdata@protonmail.com]_all-files-encrypted |
| Ransom note | A template for the ransom note is also used, and includes victim's ID and email address, f; the text of the note is not in our records |
| Contact | decyourdata@protonmail.com, backtonormal@tutanota.com and backtonormal@vistomail.com |
| 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 14 more facts
| Ransom size | Some victims were asked to pay $5,000 in Bitcoin to recover all encrypted data |
|---|---|
| Associated crypto-wallet | [payment address omitted] |
| Data decryption | The only safe way to retrieve files is by using backups, although using third-party recovery software might be helpful for some victims |
| Detection names | No Microsoft detection name is known |
| Encrypted file extension | .dat |
| 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 | 6 write-ups by security sites; details still limited |
| Encrypted files | .dat |
| Free decryptor | No free decryptor is known (checked 7 October 2026) |
| First seen | 5 February 2020 |
| Facts checked | 7 October 2026 |
- File extension:
.dat
From our report of Feb 2020 · not reviewed since
More from our earlier report on DecYourData ransomware
- Malware can cause significant damage to Windows system files.
- All your data have been locked.
- Fill subject with your ID like this: id-xxxxx Email: decyourdata@protonmail.com
How DecYourData ransomware behaves
From our report of Feb 2020 · not reviewed since
DecYourData ransomware - a file locking virus that asks users to contact hackers for a chance of restoring personal data
DecYourData ransomware is a crypto-malware that was first spotted in December 2019, with a variant appearing a month later.
Just as many other similar viruses of such type, it relies on file encryption process (which is performed with the help of AES cipher) to hold all personal files like pictures, documents, databases, videos, PDF, and others, hostage, and demand ransom payment in Bitcoin cryptocurrency for DecYourData ransomware decryption software.
Once the DecYourData virus infection is triggered, it will scan the machine for encryptable files and provide a unique ID for each victim, which will later be used for identification, payment, and decryption process.
To make sure that users know how to proceed next, malicious actors drop a ransom note "Help for decrypting id-victim ID .txt, which emails that users have to contact them via decyourdata@protonmail.com, although later version used backtonormal@tutanota.com and backtonormal@vistomail.com emails.
The encrypted data is marked per the following template: id-victim ID _all-files-encrypted. Currently, the only safe way to recover DecYourData ransomware encrypted files is by using backups, although using a few alternative methods might sometimes prove successful.
Due to relatively low prevalence of DecYourData ransomware, pinpointing its exact distribution techniques can be difficult. Nevertheless, most of file locking malware is delivered via the following methods:
As soon as the DecYourData virus breaks into a computer (it can attack all Windows versions, including the latest Windows 10), it populates various files into %TEMP%, %Users%, and other folders, one of which is typically a main executable of the malware. This file is generally used to examine particular ransomware behavior by automated sandbox tests.
Once launched, DecYourData proceeds with various system modifications, such as deletion of Shadow Volume Copies (prevents data recovery from automated backups), modification of Windows registry database (increases persistence), termination of various recovery features, etc. Due to these changes, DecYourData ransomware removal might sometimes not be successful in the normal environment, which is why experts suggest users accessing Safe Mode and only then perform a full system scan with powerful security software.
Once the preparations are complete, DecYourData ransomware proceeds with file encryption process witch appends a lengthy extension to most commonly used file types, such as .doc, .pdf, .mp4, .jpg, .dat, .mdb, .ini, etc. As a result, victims can no longer access their data, and they see a blank icon instead of an original one.
Unlike most of the other ransomware, the DecYourData virus does not use the dot, which is followed by a predetermined file extension but instead replaces it with space.
After that, a brief ransom note is presented to the infected users, which states:
Most experts recommend avoiding contact with DecYourData, as well as other ransomware authors, as there is no guarantee that they will provide a decryption tool. However, because the decryptor is unique to each victim, there is little chance of recovering data without paying criminals or negating ransomware devastating effects by using backups.
If your files are encrypted by DecYourData, and you have no backups available, you should consider what is best for you. We highly recommend avoiding paying the ransom, although it might be the only choice in some cases (you should realize that you might also lose your money, however).
Some victims who contacted cybercriminals claimed that they were asked to pay as much as $5,000 in BTC for decryption software.
- Malicious spam email attachments or hyperlinks;
- Pirated software installers or software cracks/loaders/keygens;
- Poorly protected Remote Desktop (RDP) connections;
- Exploit kits and software vulnerabilities;
- Fake updates and other executables presented on phishing sites.
From our report of Feb 2020 · not reviewed since
Data-encrypting malware can be spread via various different methods
As already stated before, there are a variety of methods that cybercriminals behind ransomware viruses can use, including exploits, fake updates, spam emails, weakly protected RDP connections, etc. Some of these methods are relatively primitive, while others are far more sophisticated and complicated, and because no anti-malware software can catch 100% of the incoming computer threats, having a security program installed is not enough to protect yourself.
One of the most prominent ransomware and other malware distribution method is spam emails, where crooks clip malicious attachments or insert hyperlinks. As a general rule, malspam campaigns use popular brand names, such as Amazon, UPS, etc., although random short email messages are common too.
With the help of email spoofing and good social engineering skills, criminals convince users to open attachments embedded with malicious macros or click on hyperlinks that would connect to a remote server and deliver the malicious ransomware payload. Thus, please do not casually open email attachments or click on links inside, unless you are sure that the email is real.
Additional protection measure tips include:
- Use strong passwords for all your accounts;
- Apply security updates for all your installed applications and the OS immediately;
- Never download pirated software installers or cracks;
- Employ additional tools for protection, such as ad-block and Firewall;
- Do not use the default TCP port for RDP and disconnect as soon as you are done using the feature;
- Backup your files regularly.
The DecYourData ransomware note
We did not record the full text of the ransom note in our report.
How to remove DecYourData 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 DecYourData 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
DecYourData 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 DecYourData 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 DecYourData 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 Feb 2020 · not reviewed since
Data recovery options and DecYourData ransomware removal method
Getting infected with ransomware is a tough situation to be in, as DecYourData ransomware removal would not restore all the encrypted files, despite the popular belief.
It is important to realize that, once files are encrypted, only a specialized decryption tool that is stored in the reach of hackers or, in some cases, third-party software might be able to work.
Note that security researchers are also constantly working on finding bugs within the encryption process of ransomware viruses, which already resulted in successful decryptor release for multiple malware families or its versions, including BigBobRoss, Djvu, Cerber, Paradise, and many others.
You can find many of such tools on the No More Ransom Project page. Thus, while there is no guarantee, it is possible that decryption software will be created for the DecYourData virus as well.
[GI=method-1]To get rid of DecYourData ransomware without interruptions, access Safe Mode with Networking:
[GI=method-2]You can also employ Safe Mode for malware removal:
Data recovery software does not decrypt files, but rather looks for working copies burred within your hard drive. The success rate of this process highly depends on how much you used the machine after the infection.
Make use of Windows Previous Versions Feature
This method could help you recover some files one-by-one if you had System Restore enabled before ransomware struck.
ShadowExplorer might sometimes recover 100% of your data
In case the DecYourData ransomware virus failed to delete Shadow Volume Copies, you should be successful in all of your data recovery with tools like ShadowExplorer.
No decryptor 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.
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 DecYourData ransomware 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 .dat and no longer open.
Setting it up step by step: 3-2-1 backups on Windows 11 and 10.
Access your website securely from any location
When you work on the domain, site, blog, or different project that requires constant management, content creation, or coding, you may need to connect to the server and content management service more often. The best solution for creating a tighter network could be a dedicated/fixed IP address.
If you make your IP address static and set to your device, you can connect to the CMS from any location and do not create any additional issues for the server or network manager that needs to monitor connections and activities. VPN software providers like can help you with such settings and offer the option to control the online reputation and manage projects easily from any part of the world.
Recover files after data-affecting malware attacks
While much of the data can be accidentally deleted due to various reasons, malware is one of the main culprits that can cause loss of pictures, documents, videos, and other important files.
More serious malware infections lead to significant data loss when your documents, system files, and images get encrypted. In particular, ransomware is is a type of malware that focuses on such functions, so your files become useless without an ability to access them.
Even though there is little to no possibility to recover after file-locking threats, some applications have features for data recovery in the system. In some cases, can also help to recover at least some portion of your data after data-locking virus infection or general cyber infection.
Questions about DecYourData ransomware
How do I open .dat files?
You cannot open them by renaming or by choosing another program. The .dat ending shows that DecYourData 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 DecYourData ransomware. Store the encrypted files on an external disk until then.
When will a decryptor for DecYourData 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 DecYourData ransomware family. A decryptor may need an original file, so keep any unencrypted copies too.
Did DecYourData ransomware steal my files or passwords?
We do not know yet. Nothing published so far shows data theft by DecYourData ransomware, but the only confirmed sign is files that end in .dat 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.
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 DecYourData ransomware get on my computer?
The way DecYourData 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 .dat 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.
Is DecYourData 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 .dat from the file names?
You can try it on a copy, but for real ransomware it will not help. The .dat 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.
My files got .dat 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 .dat 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 DecYourData 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 DecYourData 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
- Twitter: New variant #DecYourData #Ransomware (read October 7, 2026)
- Wikipedia: Advanced Encryption Standard (read October 7, 2026)
- NJCCIC: Exploit Kits (read October 7, 2026)
- Virusai: Virusai (read October 7, 2026)
- LifeHacker: How Spammers Spoof Your Email Address (and How to Protect Yourself) (read October 7, 2026)