BigLock/Corona-lock Ransomware - How to remove

Corona-lock ransomware, also known as BigLock, emerged in the middle of 2020. It locks files and renames then to end with “corona-lock”, “biglock”, “nermer”, and other extensions.

Corona-lock/BigLock is very malicious and it can cause a lot of harm. It can destroy files (such as personal photographs). Its creators demand money in exchange for fixing the files. There’s a possibility that Corona-lock installs spyware, too

This ransomware is detected by antivirus programs as Trojan, Ransom, Filecoder, Malicious, etc. It needs to be removed, however, restoring the files that it corrupted is a separate issue – and there’s no guaranteed fix.

Details on Corona-lock:

Type of threat	Ransomware.
How Corona-lock affects the computer	Encrypts (corrupts) files and renames them, installs adware, spyware, demands for money in exchange for fixing the files.
How to fix the files	Restore from a backup, if possibe, put the encrypted files on a backup and don’t edit them, wait for a free solution, use tools for restoring corrupted files, use data recovery tools.
How to remove Corona-lock	Enable task manager, remove malware with antivirus programs (Spyhunter, others).

About Corona-lock/BigLock ransomware

BigLock breaks files

Corona-lock is file-encrypting ransomware. It’s also known as CovidWorldCry and BigLock.

If some details described here don’t match your case exactly, it could also be another case, like a new version of Scarab ransomware. Its ransom note is very similar to Corona-lock’s.

Corona-lock takes various files – images, videos, documents, PDFs, text files, saves, other media and data – and runs them through a cryptographic algorithm. Corona-lock scrambles data in such a way that it appears random and loses any information that was contained there. Basically, it corrupts the files on the infected computer.

Were you to open a text file that was encrypted with Corona-lock, you’d see gibberish. If you opened an encrypted image file, you’d see a severely corrupted picture.

It demands money

To reverse the corruption, Corona-lock’s makers offer to send a decryptor and a decryption key. But they want to be paid in exchange. They say this in their ransom note.

This is a well-established criminal scheme. Each victim’s decryption key is unique, meaning that each victim needs to pay their own ransom to get back their data.

To ask for money, Corona-lock leaves a ransom note called HOW TO RECOVER ENCRYPTED FILES, README_LOCK, PROTECT_INFO.txt, etc. This ransom note includes the criminals’ contacts and threats. The note isn’t dangerous, so you might want to keep it. It can help identify the ransomware in the future.

To scare victims even more, the cybercriminals behind BigLock add some threats to the ransom note:

• They claim to have stolen personal information and they threaten to sell that data if the victim doesn’t pay.
• They say that the longer the victim waits to pay, the higher the price will be.

Then the criminals provide their email address, like [email protected]. However, it’s best to not contact the criminals because, well, they’re criminals.

How to remove Corona-lock

Manage the encrypted files

If you have a backup to restore data from, you can delete the encrypted files.

So, what are your options for getting your data back if you didn’t have a backup?

So far, there’s no free decryption tool that I know of.

If you plan on trying to decrypt or repair the files locked by BigLock, put them on a backup drive, upload them to the cloud, or use another backup method. Changes made to these files can render them undecryptable.

If you absolutely need your files decrypted right now, if you’re thinking of contacting the criminals behind BigLock, then be careful. Do not reveal them any of your personal information. And consider reporting this attack to the responsible agency in your country.

Don’t trust scammers who promise to fix your files. There’s no magic fix for ransomware. There’s a reason why cryptography is used everywhere to protect our privacy.

Remove Corona-lock

BigLock disables Task Manager, so restore the use of it. Then, you can use antivirus programs that you trust (like Spyhunter) to remove Corona-lock and other malware. Alternatively, reformat your drive.

Just make sure that the encrypted files are on a backup first.

Also, figure out how BigLock got on your PC. Once you know how ransomware infected your computer, you can better protect yourself in the future.

Automatic Malware removal tools

How to recover BigLock/Corona-lock Ransomware encrypted files and remove the virus

Step 1. Restore system into last known good state using system restore

1. Reboot your computer to Safe Mode with Command Prompt:

for Windows 7 / Vista/ XP

• Start → Shutdown → Restart → OK.
• Press F8 key repeatedly until Advanced Boot Options window appears.
• Choose Safe Mode with Command Prompt.

for Windows 8 / 10

• Press Power at Windows login screen. Then press and hold Shift key and click Restart.
• Choose Troubleshoot → Advanced Options → Startup Settings and click Restart.
• When it loads, select Enable Safe Mode with Command Prompt from the list of Startup Settings.

 

2.Restore System files and settings.

• When Command Prompt mode loads, enter cd restore and press Enter.
• Then enter rstrui.exe and press Enter again.
• Click “Next” in the windows that appeared.
• Select one of the Restore Points that are available before Corona-lock Ransomware has infiltrated to your system and then click “Next”.
• To start System restore click “Yes”.

 

Step 2. Complete removal of BigLock/Corona-lock Ransomware

After restoring your system, it is recommended to scan your computer with an anti-malware program, like Spyhunter and remove all malicious files related to Corona-lock Ransomware. You can check other tools here.  

Step 3. Restore BigLock/Corona-lock Ransomware affected files using Shadow Volume Copies

If you do not use System Restore option on your operating system, there is a chance to use shadow copy snapshots. They store copies of your files that point of time when the system restore snapshot was created. Usually Corona-lock Ransomware tries to delete all possible Shadow Volume Copies, so this methods may not work on all computers. However, it may fail to do so. Shadow Volume Copies are only available with Windows XP Service Pack 2, Windows Vista, Windows 7, and Windows 8. There are two ways to retrieve your files via Shadow Volume Copy. You can do it using native Windows Previous Versions or via Shadow Explorer. a) Native Windows Previous Versions Right-click on an encrypted file and select Properties → Previous versions tab. Now you will see all available copies of that particular file and the time when it was stored in a Shadow Volume Copy. Choose the version of the file you want to retrieve and click Copy if you want to save it to some directory of your own, or Restore if you want to replace existing, encrypted file. If you want to see the content of file first, just click Open.

b) Shadow Explorer It is a program that can be found online for free. You can download either a full or a portable version of Shadow Explorer. Open the program. On the left top corner select the drive where the file you are looking for is a stored. You will see all folders on that drive. To retrieve a whole folder, right-click on it and select “Export”. Then choose where you want it to be stored.

Step 4. Use Data Recovery programs to recover BigLock/Corona-lock Ransomware encrypted files

There are several data recovery programs that might recover encrypted files as well. This does not work in all cases but you can try this:

• We suggest using another PC and connect the infected hard drive as slave. It is still possible to do this on infected PC though.
• Download a data recovery program.
• Install and scan for recently deleted files.

Note: In many cases it is impossible to restore data files affected by modern ransomware. Thus I recommend using decent cloud backup software as precaution. We recommend checking out Carbonite, BackBlaze, CrashPlan or Mozy Home.