Crypto ransomware: what it is and how to remove it
Crypto-Blocker is a new file-encrypting virus that uses AES ciphers to make files on the targeted computer inaccessible. Malware appends .corrupted file extension to encrypted files and delivers a ransom note on the lock screen.
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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Crypto ransomware: summary
| Detection names | No Microsoft detection name is known |
|---|---|
| Ransom note | Not named in our report; the text of the note is not in our records |
| Contact | Not recorded in our earlier report |
| Encrypted file extension | .corrupted |
| 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 | Crypto |
| Type | File-encrypting ransomware |
| Symptoms | Files renamed with a new extension |
| Evidence | 3 write-ups by security sites; details still limited |
| Encrypted files | .corrupted |
| Free decryptor | No free decryptor is known (checked 7 October 2026) |
| First seen | 10 May 2017 |
| Facts checked | 7 October 2026 |
Names and addresses to look for
- File extension:
.corrupted
How Crypto ransomware behaves
From our report of May 2017 · not reviewed since
Crypto-Blocker ransomware is blackmailing people and threatening to damage their computers
Crypto-Blocker is a new file-encrypting virus that uses AES ciphers to make files on the targeted computer inaccessible.
Malware appends .corrupted file extension to encrypted files and delivers a ransom note on the lock screen. The ransom-demanding message informs about necessity to pay 10 euros, dollars or pounds within 5 hours. Otherwise, affected computer might crash. However, if you see this threatening message, you should not panic and focus on Crypto-Blocker removal.
Cyber criminals often use psychological terror to make people pay the ransom. Though, they usually are unable to damage the device or delete encrypted files. However, you should not waste your time and employ professional malware removal program. We suggest scanning your device with and remove Crypto-Blocker with the help of it.
In the ransom note, developers of the Crypto-Blocker ransomware presents themselves as the "hacker company." These shady people use a vivid language to scare victims. The threatening message informs that if users want to keep their computers "alive" they need to pay 10 euros, dollars or pounds.
However, hackers are understanding and allow victims to choose other currency if they need to pay the ransom. Indeed, it's unusual behavior because crooks often are strict about ransoms. However, they give a short amount of time to make the payment - only 5 hours.
Once victims transfer the money, they receive a code that they need to enter into the box at the bottom of the lock screen. Then, all their files should be decrypted, and Crypto-Blocker deleted from the system. Otherwise, people might face even more problems. According to the crooks, if they will not receive a ransom on time, the affected computer might crash or become "unusable."
Undoubtedly, the payment is small, and you might feel that it's worth to take the risk. However, we do not recommend spending such money and sponsoring further cyber crimes. Even one dollar is a motivation for cyber criminals to work harder and create bigger illegal projects, and your files might be still left encrypted.
From our report of May 2017 · not reviewed since
Deleting Crypto-Blocker ransomware virus from the computer
Virus elimination is completed using a powerful malware removal programs, such as , or .
However, you might not be able to install such programs easily. Malware might prevent you from simply downloading it. Then, you should be able to install your chosen software, update it and run a full system scan. Automatic Crypto-Blocker removal assures that all ransomware-related entries are deleted from the computer entirely, and cyber criminals cannot cause any other damage to you.
[GI=method-1]If Crypto-Blocker prevents from installing or accessing malware removal program, reboot your device to the Safe Mode with Networking and then try again.
[GI=method-2]System Restore is another method to disable the virus. Bear in mind that disabling is not the same as removing malware. Thus, you need to scan the device with security program as well.
This professional software is designed to restore accidentally deleted, corrupted and some of the encrypted files. Thus, it might help to rescue your files as well.
Windows Previous Versions feature might also be useful in data recovery
Windows Previous Versions feature allows traveling back in computer's time and accessing previously saved versions of the encrypted files. However, this method only works if System Restore function has been enabled before ransomware attack, and you need to restore only a few files.
ShadowExplorer might help to restore files encrypted by Crypto-Blocker ransomware
It's unknown whether malware can delete Shadow Volume Copies of the encrypted files or not. If these files are left on the system, you could use the help of the ShadowExplorer.
Crypto-Blocker Decryptor is not available yet
From our report of May 2017 · not reviewed since
Ransomware distribution and infiltration strategies
It's unknown what specific technique is used for the circulation of Crypto-Blocker virus.
Probably, cyber criminals use traditional ways to spread it, for instance, malicious spam emails, malvertising, fake updates, and exploit kits. Thus, if you want to avoid ransomware, you should take precautions, make data backups and be careful when browsing the Web. First of all, do not rush opening attachments or clicking links (or buttons) provided in the unknown email.
Crooks might send emails where they pretend to be from banks, online shops and other reputable companies or organizations, and easily trick you into opening an infected content. Crypto-Blocker might be installed on the device as soon as you click on obfuscated word or pdf document, amazing shopping offer or any online ad.
Bear in mind that this content might look legitimate and safe, so you should be critical and do not take any harsh actions. Finally, you should keep your software updated and strengthen your computer's security with professional security program.
The Crypto ransomware note
We did not record the full text of the ransom note in our report.
How to remove Crypto 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 Crypto 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
Unplug the network cable or turn off Wi-Fi, and disconnect USB drives, external disks and network shares, so Crypto cannot reach more files. Pause OneDrive, Google Drive or Dropbox sync, because synced folders upload the encrypted copies over the good ones.
Leave the PC on but offline while you read the next steps, since a restart can let the ransomware run again. This applies to Windows 11 and Windows 10 alike.
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
The name of the family decides whether a free decryptor can help. Copy the ransom note and two small encrypted files to a USB stick, and check them on another device with ID Ransomware or Crypto Sheriff.
Note the extension added to the files, the contact address and the victim ID shown in the note. Keep the originals on the Windows 11 or Windows 10 PC untouched.
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
Our last check found that for Crypto, no free decryptor is known (checked 7 October 2026). Look again yourself in the No More Ransom list and the free decryptor pages of Emsisoft, Avast and Kaspersky, which add new families every year.
A decryptor needs the ransomware gone first, or it encrypts the files again. Keep at least one copy of the encrypted files on an external drive, even if no tool works yet.
Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 4: Remove the ransomware before you restore or decrypt
Removing Crypto does not bring the files back, but it has to come first. Start with Defender's Full scan, then the offline scan from the same Scan options page, which checks the disk before Windows loads.
If the scan cannot start, use Safe Mode with Networking. Delete the ransom notes only after you have saved a copy, because removal tools sometimes leave them behind on Windows 11 and 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
Windows keeps shadow copies for restore points and backups, and some ransomware fails to delete them.
vssadmin list shadowsin an administrator Command Prompt tells you at once whether any exist.If they do, right-click the folder that held your files, open Properties > Previous Versions, select a version from before the attack, and click Open to check it before you Restore or copy the files out. Windows 11 and Windows 10 both have the tab.
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
A backup made before the attack is the surest way back. Connect it only once the PC is clean, then restore from File History, Windows Backup, OneDrive's Restore your OneDrive or your own external copies.
Without a backup, try file recovery: the originals that Crypto deleted may still be on the disk until something overwrites them. Install nothing new on the drive you want to recover from on the Windows 11 or Windows 10 PC.
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.
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.
Protect the files you restore
Restore only after the scans are clean and the PC no longer shows files that end in .corrupted and no longer open; otherwise the restored copies can be damaged again.
Then build a backup that survives the next infection:
- one copy in the cloud with version history
- one on an external drive that is disconnected between backups
- the working copy on the PC
Version history matters because a backup that syncs damaged files overwrites the good ones.
How to do this with the tools built into Windows: the 3-2-1 backup rule on 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 Crypto ransomware
Is there a decryptor for .corrupted files?
That depends on the family behind the .corrupted 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.
How do I open .corrupted files?
You cannot open them by renaming or by choosing another program. The .corrupted ending shows that Crypto 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 Crypto. Store the encrypted files on an external disk until then.
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.
Did Crypto steal my files or passwords?
We do not know yet. Nothing published so far shows data theft by Crypto, but the only confirmed sign is files that end in .corrupted 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.
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 Crypto get on my computer?
The way Crypto 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 .corrupted 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 Crypto 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.
Should I reinstall Windows after the .corrupted attack?
Reinstalling removes the ransomware but not the encryption: your files ending in .corrupted 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 removing Crypto unlock my .corrupted files?
No. Removing Crypto stops it from encrypting more files and from starting again, but it does not decrypt the files that already end in .corrupted. The scanner does not have the attackers' key.
Files come back only from a backup, from copies the ransomware did not reach, such as OneDrive version history, Previous Versions, e-mail attachments or a phone, or with a working decryptor if one exists.
Remove the ransomware first anyway: if you restore files while it is still active, it can encrypt them again. Keep the encrypted files; a decryptor may be published later.
Will Fortect remove Crypto?
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 Crypto, 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: Advanced Encryption Standard (read October 7, 2026)
- CISA: StopRansomware (read October 7, 2026)
- No More Ransom (read October 7, 2026)
- FTC: How to recognize, remove and avoid malware (read October 7, 2026)
- Microsoft Learn: Microsoft Defender Offline (read October 7, 2026)