Cryptowin Ransomware (also called BTC, CryptoByte, CrptXXX) is a deadly malware that encrypts certain files on targeted computer. Once this virus is run on the system, it immediately infects files and appends the extension with .cryptowin. It may also include the attackers email address to remind user who to contact if they wish to recover files. To site an example, encrypted document file will appear something like mydocument.doc.[firstname.lastname@example.org].cryptowin and Spreadsheet data will be mysheet.xlsx.[email@example.com].cryptowin.
To further inform user about the attack, Cryptowin will also place a text file _HOW_TO_FIX.inf on every folder whenever there are encrypted files. The message contains instructions, contact email address, and payment amount. Here are some excerpts from Cryptowin text file:
All your files have been encrypted
If you want to restore them, write us an e-mail: no.btc.protonmail.ch
You have to pay for decryption in Bitcoins. The price depends on how fast you write to us.
After payment, we will send you the decryption tool that will decrypt all your files.
FREE DECRYPTION GUARANTEE
Before paying, you can send us up to 3 files for free decryption. Please note that files must not contain valuable information and their total size must be less than 10MB…
As you can see, this attack was made solely to generate money by making your precious files unusable. You must pay the attacker before you can restore the files to its original form. With recent similar attacks, it is evident that cyber criminals are demanding huge amount of money. In the case of Cryptowin, ransom amount is unspecified. Attackers demand will be based on how soon the victim will contact them.
First discovered and Tweeted by @MarceloRivero, Cryptowin Ransomware, also changes the wallpaper as shown in the image above. Sadly, there is still no decryption key for this type of virus.
How to Remove CryptoWin Ransomware
Ransomware files are placed deeply into the system and on various locations, thus, thorough scanning is vital to totally remove CryptoWin Ransomware virus. Aside from our suggested tool, you may also run your own security program.
Though affected files may be impossible to decrypt due to complexity of the encryption, you can still try recovery method like Shadow Explorer or Previous Version as described below.
Stage 1: Scan the Computer with ESET Rogue Application Remover (ERAR)
1. Download the free scanner called ESET Rogue Application Remover.
Download Link for ERAR (this will open a new window)
2. Choose appropriate version for your Windows System. Save the file to a convenient location, preferably on Desktop.
3. After downloading the file, Windows will prompt that download has completed. Click Run to start the program. Another option is to browse the location folder and double click on the file ERARemover_.exe.
4. On ESET Rogue Application Remover SOFTWARE LICENSE TERMS, click Accept to continue.
5. The tool will start scanning the computer. It will prompt when it finds CryptoWin Ransomware virus and other malicious entities. Follow the prompt to proceed with the removal.
Stage 2: Double-check for CryptoWin Ransomware’s leftover with Microsoft’s Malicious Software Removal Tool
1. Download the free scanner called Malicious Software Removal Tool.
Malicious Software Removal Tool Download Link (this will open a new window)
2. The tool automatically checks the operating system and suggest appropriate download version. Click on Download button to begin. Save the file to a convenient location, preferably on Desktop.
3. After downloading the file, Windows will prompt that download has completed. Click Run to start scanning for CryptoWin Ransomware. Another option is to browse the location folder and double click on the file to run.
4. The tool will display Welcome screen, click Next. Please note the message “This tool is not a replacement for an antivirus product.” You must understand that this program is made specifically to find and remove malware, viruses, Trojans, and other harmful elements on the computer. It was not designed to protect the computer.
5. Next, you will see Scan Type. Please choose Full Scan to ensure that all CryptoWin Ransomware virus entities and other harmful files left on the computer will be found and removed. For advanced computer user, you can opt for Customized Scan, if there are other drives or folders you wanted to include in this scan.
6. Full scan may take a while, please wait for Malicious Software Removal Tool to complete the tasks. However, you may cancel the scan anytime by clicking on the Cancel button.
7. After scanning, the tool will reveal all identified threats. There may be other threats that our first scan fails to detect. Please remove/delete all detected items.
8. When removal procedure is complete, you may now close Malicious Software Removal Tool. We hope that CryptoWin Ransomware have been completely deleted from the computer. Please restart Windows to proceed with the normal operation.
Stage 3 : Unlocking files with CryptoWin Decryptor
1. Download BTCWareDecrypter version 126.96.36.199+. This tool was developed and shared by ransomware hunter Michael Gillespie.
Download the Program from BleepingComputer (this will open a new window)
2. After downloading, unzip and run the program.
3. Go to Settings > Find Key, and select “Use Encrypted/Original File Pair” to load the encrypted file and the original version.
4. Once the key was found and loaded, start decrypting remaining files by selecting respective Directories and press Decrypt button when ready.
Option 1: Windows Previous Version Tool
Windows Vista and Windows 7 have a feature called Previous Versions. However, this tool is only usable if restore point was made prior to CryptoWin Ransomware virus infection. To use this tool and recover files affected by the virus, please follow these steps:
1. Open My Computer or Windows Explorer.
2. Right-click on the affected files or folders. From the drop-down list, please click on Restore previous versions.
3. New window will open display all backup copy of files and folders you wanted to recover. Choose the appropriate file and click on Open, Copy, or Restore. Restoring selected files overwrites the current encrypted files on the computer.
Option 2: Use ShadowExplorer to restore files encrypted by CryptoWin Ransomware
Just like Previous Version tool, ShadowExplorer is taking advantage of shadow copy created by Windows. This tool allows you to retrieve older version of files before it was encrypted by CryptoWin Ransomware.
1. Download ShadowExplorer from the official web site.
2. Install the program with the default settings.
3. The program should run automatically after installation. If not, double-click on ShadowExplorer icon.
4. You can see the drop-down list on top of the console. Please select proper drive and the most recent point-in-time shadow copies of files you wish to restore prior to CryptoWin Ransomware infection.
5. Right-click on the Drive, Folder, or File you wish to restore and click Export…
6. Lastly, ShadowExplorer will prompt for location where you want to save the copy of recovered files.