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CTB Locker virus decryption and removal tool

3 min read
Although files ciphered by the CTB Locker ransomware are impossible to decrypt without a private key kept by criminals, there still are some recovery chances.

CTB Locker was once a highly prolific crypto malware breed but has evolved into more of a targeted threat featuring out-of-the-ordinary sophistication over time. Its immutable trait is a strong encryption routine that puts infected users into a tough dilemma circumstance: to pay up or lose their important data. The trojan under consideration leverages RSA-2048, a public-key standard that uses one key to encrypt files and another to decrypt them. The primary hurdle in a ransomware attack scenario is that the latter key is in extortionists’ hands and can only be obtained if the victim pays a Bitcoin equivalent of about $300. The scammers have recently changed their tactic by encoding the content of websites and demanding a smaller amount of 0.4 BTC, or less than $200. One way or another, it’s a vicious malady that targets both individual users and webmasters.

CTB Locker instructing a victim in data decryption
CTB Locker instructing a victim in data decryption

When the CTB Locker process is executed on a Windows machine, it performs the crypto job with regard to a predefined range of file extensions consisting of hundreds of different formats. The malware also adds three files into every folder in which at least one files has been locked. These documents with ransom demands are named DecryptAllFiles.txt, AllFilesAreLocked.bmp and [7 random characters].html. The warning message in each of the above says “Your personal files are encrypted by CTB-Locker. Your documents, photos, databases and other important files have been encrypted with strongest encryption and unique key generated for this computer.” If the user refuses to submit the money during 96 hours since the compromised began, the ransom will become twice as big.

Contents of a phishing email involved in CTB Locker circulation
Contents of a phishing email involved in CTB Locker circulation

The operators of this campaign stick with a fairly simple but very effective distribution scheme – they literally fool people into launching the malicious payload. Target users receive an email disguised as a Fax notification, a package delivery report with status tracking code, a payroll or some other arresting subject. The ZIP file attached to this message, when extracted, runs the ransomware executable stealthily enough for the person not to notice.

Data encryption is definitely not a weak link of CTB Locker – it is impossible to bypass and implemented professionally. Some recovery vectors, though, can do the trick partially or fully as they harness flaws that may vary from incident to incident. Of course, the optimal way out is to remove the ransom trojan proper and download ciphered files from backup, but not everyone maintains those. The part below covers all worthwhile techniques to mitigate the damage.

Automated removal of CTB Locker virus

Owing to an up-to-date database of malware signatures and intelligent behavioral detection, the recommended software can quickly locate the infection, eradicate it and remediate all harmful changes. So go ahead and do the following:

1. Download and install the antimalware tool. Open the solution and have it check your PC for PUPs and other types of malicious software by clicking the Start Computer Scan button

Download CTB Locker remover

2. Rest assured the scan report will list all items that may harm your operating system. Select the detected entries and click Fix Threats to get the troubleshooting completed.

Ways of non-ransom recovery of encrypted files

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 CTB Locker 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.
Shadow Explorer

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 Data Recovery Pro by ParetoLogic features this type of capability therefore it can be applied in ransom attack scenarios to at least get the most important files back. So download and install the program, run a scan and let it do its job.

Download Data Recovery Pro

Data Recovery Pro

Ransomware Prevention Tips

To avoid the CTB Locker 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.

Download CTB Locker ransomware removal tool


  1. Janice Case

    May 17, 2016 at 4:24 am

    Dear In Charge,

    How to fix my files are encrypted with RSA -2048 and AES-128 ciphers.




    • admin

      September 3, 2016 at 11:26 am


      Have you tried the instructions covered in this post? Give them a shot if you haven’t yet.


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