What is ‘Your personal files are encrypted by CTB-Locker’?
The CTB-Locker ransomware virus infiltrates operating systems via infected email messages and fake downloads (for example, rogue video players or fake Flash updates). After successful infiltration, this malicious program encrypts files (*.doc, *.docx, *.xls, *.ppt, *.psd, *.pdf, *.eps, *.ai, *.cdr, *.jpg, etc.) stored on computers and demands payment of a $300 ransom (in Bitcoins) to decrypt them (encrypted documents receive a .ctbl files extension). Cyber criminals responsible for releasing this rogue program ensure that it executes on all Windows operating system versions (Windows XP, Windows Vista, Windows 7, and Windows 8). Critroni ransomware creates AllFilesAreLocked.bmp DecryptAllFiles.txt and [seven random letters].html files within each folder containing the encrypted files.
These files contain instructions detailing how users may decrypt their files, and on use of the Tor browser (an anonymous web browser). Cyber criminals use Tor to hide their identities. PC users should beware that while the infection itself is not complicated to remove, decryption of files (encrypted using RSA 2048 encryption) affected by this malicious program is impossible without paying the ransom. At time of research, there were no tools or solutions capable of decrypting files encrypted by Critroni. Note that the private key required to decrypt the files is stored by the CTB-Locker command-and-control servers, which are managed by cyber criminals. Therefore, the best solution is to remove this ransomware virus and then restore your data from a backup.
Ransomware infections such as CTB-Locker (including CryptoWall, CryptoDefense, CryptorBit, and Cryptolocker) present a strong case to maintain regular backups of your stored data. Note that paying the ransom as demanded by this ransomware is equivalent to sending your money to cyber criminals – you will support their malicious business model and there is no guarantee that your files will ever be decrypted. To avoid computer infection with ransomware infections such as this, express caution when opening email messages, since cyber criminals use various catchy titles to trick PC users into opening infected email attachments (for example, “UPS Exception Notification” or “FedEx Delivery Failure Notification”). Research shows that cyber criminals also use P2P networks and fake downloads containing bundled ransomware infections to proliferate Critroni. Currently, the ‘Your personal files are encrypted’ ransomware threat is delivered in the English and Russian languages, and therefore, countries speaking these languages are at the top of the target list of cyber criminals proliferating this malware.
Update 2015 January 20 – Cyber criminals have released an updated version of CTB-Locker ransomware targeting USA, Italy, Netherlands, and Germany. This variant is mostly distributed using fake fax notification emails with infected attachments. Cyber criminals have also extended a time frame in which their victims must pay the ransom to regain control of their files to 96 hours (previously, 72 hours):
Message presented in AllFilesAreLocked.bmp DecryptAllFiles.txt and [7 random letters].html files:
Your documents, photos, databases and other important files have been encrypted with strongest encryption and unique key, generated for this computer. Private decryption key is stored on a secret Internet server and nobody can decrypt your files until you pay and obtain the private key. If you see the main locker window, follow the instructions on the locker. Otherwise, it’s seems that you or your antivirus deleted the locker program. Now you have the last chance to decrypt your files.
1. Type the address hxxp://torproject.org in your Internet browser.
It opens the Tor site.
2. Press ‘Download Tor’, then press ‘DOWNLOAD Tor Browser Bundle’,
install and run it.
3. Now you have Tor Browser. In the Tor Browser open the hxxp://zaxseiufetlkwpeu.onion
Note that this server is available via Tor Browser only.
Retry in 1 hour if site is not reachable.
4. Copy and paste the following public key in the input form on server. Avoid missprints.
5. Follow the instructions on the server.
Cyber criminals have started using a fake Windows 10 update email message with an infected attachment to spread this ransomware (the infected file is called “Win10Installer.zip” – please don’t download this attachment):
Screenshot of an infected email message used in ‘Your personal files are encrypted’ ransomware distribution:
Text presented within infected email messages:
Subject: UPS notification
From: United Parcel Service (0511notify (at) ups.com)
This is a follow-up on your package delivery (tracking number 0p2uYq5RIho). The package contained in the above-mentioned shipment was not accepted at the destination address. Please contact your local UPS office and produce the printed delivery sticker, included in this email attachment. Please note that in case of a failure to contact your local UPS office within 21 days the parcel will be returned to sender.
Happy to serve you,
This is automatically generated delivery status email, please do to reply to it.
Screenshot of the AllFilesAreLocked.bmp file:
Screenshot of the DecryptAllFiles.txt file:
Screenshot of the [seven random letters].html file:
‘Your personal files are encrypted’ ransomware payment page:
Message presented on the ‘Your personal files are encrypted’ ransom payment page:
Server accepts payments in Bitcoin (BTC) only.
1. Pay amount of 0.2 BTC (about of 24 USD) to address – Bitcoin wallet address.
2. Transaction will take about 15-30 minutes to confirm.
Decryption will start automatically. Do not: power off computer, run antivirus program, disable Internet connection. Failures during key recovery and file decryption may lead to accidental damage of files. If you have no Bitcoins press ‘Exchange’.
Critroni currency exchange page:
Screenshot of CTB-Locker affiliate server:
Cyber criminals responsible for creating CTB-Locker ransomware are using an affiliate scheme to spread their malware. Affiliates who register and distribute CTB-Locker receive 70% of the profits generated by this ransomware.
Note: at time of writing, there were no known tools capable of decrypting files encrypted by CTB-Locker without paying the ransom. By following this removal guide, you will be able to remove this ransomware from your computer, however, the affected files will remain encrypted. We will update this article as soon as there is more information available regarding decryption of compromised files.
CTB-Locker virus removal:
Quick solution to remove CTB-Locker
Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, then select Safe Mode with Networking from the list.
Video showing how to start Windows 7 in “Safe Mode with Networking”:
Windows 8 users: Go to the Windows 8 Start Screen, type Advanced, in the search results select Settings. Click on Advanced Startup options, in the opened “General PC Settings” window select Advanced Startup. Click on the “Restart now” button. Your computer will now restart into “Advanced Startup options menu”. Click on the “Troubleshoot” button, then click on “Advanced options” button. In the advanced option screen click on “Startup settings”. Click on the “Restart” button. Your PC will restart into the Startup Settings screen. Press “5” to boot in Safe Mode with Networking.
Video showing how to start Windows 8 in “Safe Mode with Networking”:
Log in to the account infected with the CTB-Locker virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.
If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.
Video showing how to remove ransomware virus using “Safe Mode with Command Prompt” and “System Restore”:
1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.
2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.
3. Next, type this line: rstrui.exe and press ENTER.
4. In the opened window, click “Next”.
5. Select one of the available Restore Points and click “Next” (this will restore your computer system to an earlier time and date, prior to the CTB-Locker ransomware virus infiltrating your PC).
6. In the opened window, click “Yes”.
7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining Critroni files.
To restore individual files encrypted by this ransomware, try using the Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of CTB-Locker are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.
To restore a file, right-click on it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the “Restore” button.
If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode, thus making its removal complicated. For this step, you require access to another computer.
To protect your computer from file encrypting ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and EasySync CryptoMonitor, which artificially implant group policy objects into the registry to block rogue programs such as CTB-Locker.
HitmanPro.Alert CryptoGuard – detects encryption of files and neutralises such attempts without need for user intervention:
EasySync CryptoMonitor – kills an encryption infection and blacklists it from running again:
Other tools known to remove CTB-Locker ransomware: