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Cryptolocker removal tool and file decryption

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The article covers must-know facts about Cryptolocker, an advanced persistent Trojan that applies uncrackable RSA cipher to encode victims’ data.

It has been around three years since the first fully functional instances of encryption-based ransomware emerged. The threat landscape has changed considerably over this period, but some infections from this cluster stay and still thrive. The malicious program known as Cryptolocker typifies such an inviolability. Although it has gone through several critical ups and downs, its recurrent iterations never failed to hit the headlines due to the invariably large attack surface, unbeatable cryptographic grip on infected users’ personal files, and high success rate of payload serving. The way this crimeware deploys encryption is tricky as it actually leverages an amalgam of RSA and AES, thus leaving hardly any data recovery options for the assaulted person other than paying the ransom.

Cryptolocker user interface with ransom demands
Cryptolocker user interface with ransom demands

Incidentally, the recent edition of Cryptolocker mentions RSA-4096 asymmetric cipher on its warning screen, but this isn’t quite true. The entropy is in fact smaller as the keys are 2048 bits long, but it’s still enough to make the decryption vector of file recovery efforts null and void. Anyway, it takes this ransomware some time before it gets down to the crypto job proper. The first thing it does on a contaminated Windows computer is it adjusts the work of the host system in its own way by adding autostart values and disabling VSS (Volume Shadow Copy Service) to prevent easy file restoration. The next stage is a scan of all letter volumes both on the hard drive and the adjacent network if any. Unmapped network shares are not at risk.

A wallpaper image set by Cryptolocker
A wallpaper image set by Cryptolocker

Once the list of the victim’s personal files has been compiled, Cryptolocker triggers the encryption routine and makes them inaccessible. Some versions of the malware contort the appearance of files by modifying the filenames and adding bizarre extensions. It’s only at this point that the Trojan notifies the user of the attack. It displays a UI with a warning message and configures an image with ransom instructions to replace the original desktop wallpaper. According to the notifications, the victim has to pay 0.5-1 Bitcoin during 72 hours. The payment processing service is built into the program’s pane, so the person can navigate back and forth using the toggles provided.

Should the ransom not be submitted in time, the extortionists threaten the target to erase the private decryption key from their Command & Control server. In plain language, this means that the data will remain locked for good. Under certain circumstances, though, it may be possible to reanimate some files through the use of specially crafted recovery tools. Furthermore, Shadow Copies of some items may not be lost if the ransomware has failed to terminate the respective service. All in all, there might be a little bit of chance for remediation.

Cryptolocker ransomware automated removal and data recovery

When faced with ransomware like Cryptolocker, one of the best shortcuts in terms of removal is to use Combo Cleaner, a lightweight and incredibly effective application with PC security and optimization features under the hood. It detects and thoroughly deletes threats while giving you insights into the overall health of your computer.

This program’s protection power spans modules that forestall all known types of malware, including ransomware and browser hijackers, and take your online security to the next level by blocking phishing sites and other suspicious web pages. Follow these simple steps to eliminate the infection for good:

1. Download Combo Cleaner installer.

Download Cryptolocker remover

Combo Cleaner scans your PC with no strings attached, but you’ll have to buy its fully functional version to remove the threats it detects. The disk optimization tools that find large files and duplicates are free to use.

Download and run Combo Cleaner installer on your PC

2. Open the CCSetup.exe file to get started. Several subsequent screens will allow you to make initial customizations so that the program works exactly as you need from the get-go.Setup customizations

3. The installation will be followed by an update of malware signatures. Once this process is through, click the Start Scan button in the left-hand sidebar.Start initial scan

4. Combo Cleaner will then check system locations that are most often polluted by Windows malware. The first scan can take a while to finish.Combo Cleaner scan in progress

5. Combo Cleaner will display a system tray notification as soon as the scan is over. Click the Resolve found threats button to view the results.Scan completed

6. The scan summary shows the names and types of the detected threats as well as their statuses and locations. Click the Remove all threats button and follow further on-screen prompts to get rid of these items.Scan results

Data recovery toolkit to the rescue

Some strains of ransomware are known to delete the original files after the encryption routine has been completed. As hostile as this activity appears, it can play into your hands. There are applications designed to revive the information that was obliterated because of malfunctioning hardware or due to accidental removal. The tool called Stellar Data Recovery features this type of a capability and therefore it can be applied in ransom attack scenarios to at least get the most important files back. So use the app to get an idea of what data can be restored and let it do the recovery job. Here is a step-by-step walkthrough:

1. Download and install Stellar Data Recovery.

Download Stellar Data Recovery

2. Open the application, select the types of recoverable files to look for, and click Next.Stellar Data Recovery main screen

3. Choose the areas you want the tool to recover from and click the Scan button.Select which PC areas to recover from

4. Having scanned the specified locations, the program will display a notification about the total amount of recoverable data. Close the dialog and click the Recover button. This will hopefully help you get some of your valuable files back.Recover files

Cryptolocker ransomware manual removal and file recovery

Some ransomware strains terminate themselves after completing the encryption job on a computer, but some don’t. Furthermore, the Cryptolocker virus may prevent victims from using popular antimalware tools in order to stay on board for as long as possible. Under the circumstances, it may be necessary to utilize the Safe Mode with Networking or System Restore functionality.

Remove Cryptolocker ransomware using Safe Mode with Networking

Remove Cryptolocker ransomware using Safe Mode with Networking

Get rid of Cryptolocker ransomware using System Restore

Get rid of Cryptolocker ransomware using System Restore

System Restore enables Windows users to roll back all changes made to the OS since the latest restore point creation time. This feature can help eliminate the most persistent ransomware. Before going this route, though, make sure System Restore had been enabled prior to the breach, otherwise the method will be inefficient.

  • Open Windows Advanced Options Menu as described in the previous section: hit F8 repeatedly when the PC is starting up. Use arrow keys to highlight the Safe Mode with Command Prompt entry. Hit Enter.Safe Mode with Command Prompt
  • In the Command Prompt window, type cd restore and hit Entercd restore command
  • Type rstrui.exe in the new command line and press EnterType rstrui.exe command
  • When the System Restore screen pops up, click Next, select a restore point that predates the contamination, and use the application’s controls to roll back the system to this earlier state.System Restore window
Be advised that even after the ransomware is removed, files will still be encrypted and inaccessible. The malicious code cleanup part, however, is important because it keeps a relapse of the infection from occurring further on and eliminates all opportunistic malware.

Ways of non-ransom file recovery

Cracking the crypto used by this ransom Trojan is more of a science fiction thing rather than an attainable prospect for the masses. This is why the troubleshooting in predicaments of this sort is a matter of two approaches: one is to pay the ransom, which isn’t an option for many victims; and the other is to apply instruments that take advantage of the ransomware’s possible weaknesses. If the latter is your pick, the advice below is a must-try.

Backups can make your day

Backups can make your day

Not only are you a lucky person in case you’ve been backing up your most important files, but you’re also a wise and prudent user. This isn’t necessarily a resource-heavy activity these days – in fact, some providers of online services are allocating a sufficient size of cloud storage space for free so that every customer can easily upload their critical data without paying a penny. Having removed the Cryptolocker ransomware, therefore, all you have to do is download your stuff from the remote server or transfer it all from an external piece of hardware if that’s the case.

Restore previous versions of encrypted files

Restore previous versions of encrypted files

A positive upshot of using this technique depends on whether or not the ransomware has erased the Volume Shadow Copies of the files on your PC. This is a Windows feature that automatically makes and keeps the backups of data elements on the hard drive as long as System Restore is enabled. The cryptoware in question is programmed to switch off the Volume Shadow Copy Service (VSS), but it has reportedly failed to in some cases.

Checking one’s options regarding this workaround is doable in two ways: through the Properties menu of each file or by means of the remarkable open-source tool called Shadow Explorer. We recommend the software-based way because it’s automated, hence faster and easier. Just install the app and use its intuitive controls to get previous versions of the encrypted objects reinstated.

Shadow Explorer

Alternatively, you can leverage the Previous Versions feature, which is native to Windows operating system. This method is more cumbersome that the use of ShadowExplorer, but it can help restore the most important individual files on condition that the ransomware failed to disable the Volume Snapshot Service on the computer. Right-click on a file of choice and select Properties. Then, go to the Previous Versions tab as illustrated below.

Previous Versions

Go ahead and pick the file’s latest backup version on the list. Use the Copy or Restore buttons to reinstate this object to a new path or to its original folder, respectively.

Ransomware Prevention Tips

To avoid Cryptolocker ransomware and other file-encrypting infections in the future, follow several simple recommendations:

  • Toggle your email provider’s anti-spam settings to filter out all the potentially harmful incoming messages. Raising the bar beyond the default protection is an important countermeasure for ransom Trojans
  • Define specific file extension restrictions in your email system. Make sure that attachments with the following extensions are blacklisted: .js, .vbs, .docm, .hta, .exe, .cmd, .scr, and .bat. Also, treat ZIP archives in received messages with extreme caution
  • Rename the vssadmin.exe process so that ransomware is unable to obliterate all Shadow Volume Copies of your files in one shot
  • Keep your Firewall active at all times. It can prevent crypto ransomware from communicating with its C&C server. This way, the threat won’t be able to obtain cryptographic keys and lock your files
  • Back up your files regularly, at least the most important ones. This recommendation is self-explanatory. A ransomware attack isn’t an issue as long as you keep unaffected copies of your data in a safe place
  • Use an effective antimalware suite. There are security tools that identify ransomware-specific behavior and block the infection before it can do any harm.

These techniques are certainly not a cure-all, but they will add an extra layer of ransomware protection to your security setup.

Revise your security status

Post-factum assessment of the accuracy component in malware removal scenarios is a great habit that prevents the comeback of harmful code or replication of its unattended fractions. Make sure you are good to go by running an additional safety checkup. Another benefit of using the antimalware tool is that it will keep ransomware threats from intruding on your computer further on.

Download Cryptolocker removal tool

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