Remove Cr1ptT0r ransomware and decrypt files

Posted on March 9, 2019

6 min read

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Cr1ptT0r to exploit DNS-320 vulnerabilities, encrypt NAS and network computers’ data for some bitcoins

What is Cr1ptT0r ransomware?
Cr1ptT0r ransomware automated removal and data recovery
Cr1ptT0r ransomware manual removal and file recovery
Ransomware Prevention Tips

What is Cr1ptT0r ransomware?

Cr1ptT0r exploits vulnerabilities in a particular outdated firmware to have itself installed on the computer systems. Specifically, it targets D-Link DNS-320. The latter is an embedded system meant to store data as a network attached storage (NAS). NAS enables storing and sharing data in its own file system. The data typically does not go online. When it does, like in the case of DNS-320, there is a huge risk of ransomware and other viral invasions.

D-Link does not promote sells of DNS-320, but official maintenance is still available. A good deal of users still sticks to using this hardware. With its latest update taking place back in 2016, DNS-320 is an open gateway for any kind of viruses.

Cr1ptT0r is not that widely known threat. Its detection rate by major security software vendors remains very low. This further increases exposure of target devices to its attacks.
The ransomware is not a product designed by co-users of a NAS. It is the bug they get when exchanging information with the web and direct sources.

That is to say, there are the following underlying ways for the virus to get into your operating system. First and the most common option leverages the exposure of DNS-320 to the internet. The other options imply the virus infects a particular user in the network hosting the NAS. The user further transfers the virus to the NAS.

Once the ransomware completes its installation, it proceeds with scanning the memory available. The greatest damage reported so far is due to its encryption of the data on the NAS affected. This might be a concern for multiple users sharing the NAS. The information stored at such an embedded system is typically of certain commercial value. The stakes are high.

The price demanded by the ransomware is available from the ransom note it delivers upon landing. The file dubbed “_FILES_ENCRYPTED_README.txt” provides a standard introduction that claims the encryption has been applied to the files on the device in question. Further details, according to its message, are available from the attackers’ website openbazaar.com. It is actually a decryption-for-ransom contact point selling decryption for the victims. The price is currently ranging around 0.3 BTC (circa USD 1200). The victims also can decrypt a particular file for USD 20.

As regards the virus itself and its behavior, it is an ELF ARM binary that uses asymmetric encryption with a 256-bit public key. The key itself is available in “cr1ptt0r_logs.txt” file dropped as a part of the ransomware. The key does not match the private key, hence of no use for decryption purposes. However, the file might be useful for decryption as it contains the list of files scrambled by the ransomware. The important conclusion from this is that the victims should not remove Cr1ptT0r before allowing for due examination of its components. Once the examination has completed, the Cr1ptT0r removal is a must.

The ransomware does not append a visible extension to the files it encrypts. The IT researchers recognized its name from the end-of-file signature, which is not a part of the filename as seen by the users.

The best practices for handling the ransomware attack and the methods enabling to get rid of Cr1ptT0r encryption are available below.

Cr1ptT0r ransomware automated removal and data recovery

When faced with ransomware like Cr1ptT0r, 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 Cr1ptT0r 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.}

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.

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.

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.

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.

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.

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.

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

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.

Cr1ptT0r 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 Cr1ptT0r 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 Cr1ptT0r ransomware using Safe Mode with Networking

Get rid of Cr1ptT0r 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.
In the Command Prompt window, type cd restore and hit Enter
Type rstrui.exe in the new command line and press Enter
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.

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 recovery of files encrypted by Cr1ptT0r ransomware

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

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 Cr1ptT0r 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

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.

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.

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 Cr1ptT0r 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 Cr1ptT0r removal tool