Can ‘.encrypted Virus’ Files Be Restored?

There are several ransomware pieces that append an ‘.encrypted’ extension to the victim’s filenames. Thus, such ransomware are often referred to as ‘.encrypted viruses’. One such threat is ZeroLocker that has been known to security researchers since 2014. Another ransomware using the .encrypted extension is TorrentLocker which later was renamed to Crypt0L0cker, both known to researchers for a while now.

In the last couple of days, several users have contacted us saying that their files have been changed and now have an ‘.encrypted’ extension. This could mean two things – either one of the ransomware cases mentioned above has been just revived, or there’s a new crypto malware using the same file extension (possibly created by affiliates).

The good news is that there’s а decryption utility available for ZeroLocker. Proceed with reading to learn more.

What Is ZeroLocker?

Clearly, it is a piece of devastating crypto malware that sneaks into a victim’s machine and encrypts their files, demanding ransom in exchange for the files’ decryption.

What we know about ZeroLocker (via Bleeping Computer’s analysis):

• ZeroLocker uses AES encryption, expect when the files are located in certain folders or are larger than 20 MegaBytes;
• Folders that are spared from encryption are any that contain any of the following words in their names – Windows, WINDOWS, Program Files, ZeroLocker, Desktop;
• Files encrypted by ZeroLocker have an .encrypted extension appended to their file names;
• Once the encryption process has finished, the ransomware will run the C:\Windows\System32\cipher.exe /w:C:\ command, and will overwrite all deleted data on the victim’s C:\ drive to get in the way of using a recovery tool;
• ZeroLocker also creates the C:\ZeroLocker folder where it stores various files and the decryptor executable named ZeroRescue.exe; the latter runs automatically upon system reboot via a new registry entry.

What about Shadow Volume Copies?

When we researched the threat back in 2014, we discovered that it didn’t affect Shadow Volume Copies.

Currently, we cannot provide any information as to whether ZeroLocker’s source code has been recently modified to affect Shadow Volume Copies. Nonetheless, a decryptor for ZeroLocker is available and it was created by Vinsula .

Here’s what Vinsula say about their utility:

• The recovery utility we have developed is a Windows console application that scans a single encrypted executable to uncover the encryption key. The operation uses a brute-force method and is CPU-bound (compute-bound). In our tests, the utility typically takes less than a day to find an encryption key, but in a worst-case scenario it could take up to 5 weeks. The utility can brute force an encrypted binary executable on either an infected machine or on a different, dedicated machine. The faster the machine (more CPU cores), the faster the brute force process takes to resolve the encryption key.
• No Internet connection is required for the process to run and scan for the encryption key. The utility doesn’t have any external dependencies. For the brute forcing option the tool needs only to have access to a single encrypted binary executable.

N.B. The Vinsula recovery utility applies only to files encrypted by ZeroLocker. If your files have an ‘.encrypted’ extension but this utility doesn’t decrypt them, you have been hit by another ransomware.

Here is an example of an ‘.encrypted’ file:

• es.gamma01.xla.encrypted (via a user post on GitHub).

What Is Crypt0L0cker?

Crypt0L0cker attacks were registered in the spring of 2015. That is when security analysts revealed that Crypt0L0cker is in fact a new version of the well-known TorrentLocker. However, Crypt0 appeared to be Geo-Locked and as such, wouldn’t attack US based machines. As with many other ransomware cases, Crypt0 was mainly distributed in spam email campaigns, pretending to be government notices.

Learn More about TorrentLocker

The communication methods used by Crypt0 were quite similar to TorrentLocker’s. When installed on victim’s system, Crypt0L0cker would connect to a Command & Control server and transmit the victim’s unique identifier and a campaign ID.

Crypt0L0cker would then scan all hard drive letters and encrypt certain files, while others are excluded. Encrypted files would have an ‘.encrypted’ extension at the end.

What about Shadow Volume Copies?

Once activated, Crypt0L0cker would delete Shadow Volume Copies and thus make the files’ restoration quite difficult, if not impossible.

Unfortunately, there is still no solution to either Crypt0L0cker or TorrentLocker.

You can still refer to the instructions below to clean your system from ransomware and back up your data.

We will keep you posted if a decryption tool for Crypt0L0cker/ TorrentLocker is developed. You can also leave a comment in our security forums.

1. Boot Your PC In Safe Mode to isolate and remove ZeroLocker, Crypt0L0cker

Boot Your PC Into Safe Mode

1. For Windows 7,XP and Vista. 2. For Windows 8, 8.1 and 10.

For Windows XP, Vista, 7 systems:

1. Remove all CDs and DVDs, and then Restart your PC from the “Start” menu.
2. Select one of the two options provided below:

– For PCs with a single operating system: Press “F8” repeatedly after the first boot screen shows up during the restart of your computer. In case the Windows logo appears on the screen, you have to repeat the same task again.

– For PCs with multiple operating systems: Тhe arrow keys will help you select the operating system you prefer to start in Safe Mode. Press “F8” just as described for a single operating system.

3. As the “Advanced Boot Options” screen appears, select the Safe Mode option you want using the arrow keys. As you make your selection, press “Enter“.

4. Log on to your computer using your administrator account

While your computer is in Safe Mode, the words “Safe Mode” will appear in all four corners of your screen.

Step 1: Open the Start Menu

Step 2: Whilst holding down Shift button, click on Power and then click on Restart.
Step 3: After reboot, the aftermentioned menu will appear. From there you should choose Troubleshoot.

Step 4: You will see the Troubleshoot menu. From this menu you can choose Advanced Options.

Step 5: After the Advanced Options menu appears, click on Startup Settings.

Step 6: Click on Restart.

Step 7: A menu will appear upon reboot. You should choose Safe Mode by pressing its corresponding number and the machine will restart.

2. Remove ZeroLocker, Crypt0L0cker with SpyHunter Anti-Malware Tool

Remove ZeroLocker, Crypt0L0cker with SpyHunter Anti-Malware Tool

1. Install SpyHunter to scan for and remove ZeroLocker, Crypt0L0cker.2. Scan with SpyHunter to Detect and Remove ZeroLocker, Crypt0L0cker.

Step 1:Click on the “Download” button to proceed to SpyHunter’s download page.

It is highly recommended to run a scan before purchasing the full version of the software to make sure that the current version of the malware can be detected by SpyHunter.

Step 2: Guide yourself by the download instructions provided for each browser.
Step 3: After you have installed SpyHunter, wait for it to automatically update.

Step1: After the update process has finished, click on the ‘Scan Computer Now’ button.

Step2: After SpyHunter has finished scanning your PC for any ZeroLocker, Crypt0L0cker files, click on the ‘Fix Threats’ button to remove them automatically and permanently.

Step3: Once the intrusions on your PC have been removed, it is highly recommended to restart it.

3. Back up your data to secure it against infections and file encryption by ZeroLocker, Crypt0L0cker in the future

Back up your data to secure it against attacks in the future

IMPORTANT! Before reading the Windows backup instructions, we highly recommend to back up your data automatically with cloud backup and insure it against any type of data loss on your device, even the most severe. We recommend reading more about and downloading SOS Online Backup .

SOS Online Backup

To back up your files via Windows and prevent any future intrusions, follow these instructions:

1. For Windows 7 and earlier 1. For Windows 8, 8.1 and 10 1. Enabling the Windows Defense Feature (Previous Versions)

1-Click on Windows Start Menu

2-Type Backup And Restore
3-Open it and click on Set Up Backup

4-A window will appear asking you where to set up backup. You should have a flash drive or an external hard drive. Mark it by clicking on it with your mouse then click on Next.

5-On the next window, the system will ask you what do you want to backup. Choose the ‘Let Me Choose’ option and then click on Next.

6-Click on ‘Save settings and run backup’ on the next window in order to protect your files from possible attacks by ZeroLocker, Crypt0L0cker.

1-Press Windows button + R

2-In the window type ‘filehistory’ and press Enter

3-A File History window will appear. Click on ‘Configure file history settings’

4-The configuration menu for File History will appear. Click on ‘Turn On’. After its on, click on Select Drive in order to select the backup drive. It is recommended to choose an external HDD, SSD or a USB stick whose memory capacity is corresponding to the size of the files you want to backup.

5-Select the drive then click on ‘Ok’ in order to set up file backup and protect yourself from ZeroLocker, Crypt0L0cker.

1- Press Windows button + R keys.

2- A run windows should appear. In it type ‘sysdm.cpl’ and then click on Run.

3- A System Properties windows should appear. In it choose System Protection.

5- Click on Turn on system protection and select the size on the hard disk you want to utilize for system protection.
6- Click on Ok and you should see an indication in Protection settings that the protection from ZeroLocker, Crypt0L0cker is on.

Restoring a file via Windows Defense feature:
1-Right-click on the encrypted file, then choose Properties.

2-Click on the Previous Versions tab and then mark the last version of the file.

3-Click on Apply and Ok and the file encrypted by ZeroLocker, Crypt0L0cker should be restored.

4. Decrypt files encrypted by ZeroLocker, Crypt0L0cker

Decrypt Files Encrypted by ZeroLocker, Crypt0L0cker

Security engineers strongly advise users NOT to pay the ransom money and attempt restoring the files using other methods.
Luckily, Emsisoft have discovered that the UmbreCrypt’s source code is the same as HydraCrypt and CrypBoss. And they have a working decrypter software you can download:

http://emsi.at/DecryptHydraCrypt

You can read the full details on their blog site.

If the decryptor mentioned above doesn’t work, wait for an update or try to bring back your files via data recovery software. Here are some examples of data recovery programs:

• Stellar Phoenix Windows Data Recovery
• Stellar Phoenix Photo Recovery
• ESupport UndeletePlus
  

Optional: Using an Alternative Anti-Malware Tool

Remove ZeroLocker, Crypt0L0cker Using an Alternative Anti-Malware Tool

STOPZilla Anti Malware

1. Download and Install STOPZilla Anti-malware to Scan for And Remove ZeroLocker, Crypt0L0cker.
Step 1: Download STOPZilla by clicking here.
Step 2: A pop-up window will appear. Click on the ‘Save File’ button. If it does not, click on the Download button and save it afterwards.

Step 3: After you have downloaded the setup, simply open it.
Step 4: The installer should appear. Click on the ‘Next’ button.

Step 5: Check the ‘I accept the agreement’ check circle if not checked if you accept it and click the ‘Next’ button once again.

Step 6: Review and click on the ‘Install’ button.

Step 7: After the installation process has completed click on the ‘Finish’ button.

2. Scan your PC with STOPZilla Anti Malware to remove all ZeroLocker, Crypt0L0cker associated files completely.
Step 1: Launch STOPZilla if you haven’t launched it after install.
Step 2: Wait for the software to automatically scan and then click on the ‘Repair Now’ button. If it does not scan automatically, click on the ‘Scan Now’ button.

Step 3: After the removal of all threats and associated objects, you should Restart your PC.

Milena Dimitrova

An inspired writer, focused on user privacy and malicious software. Enjoys 'Mr. Robot' and fears '1984'.

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