PyCL ransomware returns and continues attacking computer users worldwide
PyCL virus seems to be another big thing in the ransomware industry. Despite that it is a brand new ransomware virus, everything that we know about it makes us presume that it is going to be distributed on a large scale. This virus is also known as Pay_creditcard ransomware. It has been programmed in Python[1] language, whereas common ransomware viruses are built in C++ programming language.
The virus is spread in the form of NSIS installer[2], and this technique is known to be used for Cerber ransomware distribution[3]. Once on the computer system, PyCL malware extracts some .txt files to %AppData%\Roaming\How_Decrypt_My_Files\ folder.
These extracted files are called index.html, pay_creditcard.html, read_me.txt, send_btc.html and style.css. We can call these as parts that all make up a ransom note (a message from cyber criminals). The virus extracts the rest of its components to %AppData%\Roaming\cl folder, connects to a Command & Control[3] (C&C) server and launches cl.exe file.
This file carries the malicious payload and starts encrypting files stored on the victim’s computer system right away. During this process, it corrupts images, videos, music files, documents, archives, and various other files, making exceptions only for files stored in system folders.
Following this procedure, the ransomware deletes Volume Shadow Copies[4] from the system, but only if the user has admin’s privileges on the compromised computer.
Then the ransomware virus connects to its C&C server again to make a POST request to 170.254.236.102/init. The indicated request transfers some information about the victim, including his Windows version, computer name, username, processor architecture, and more.
The server then sends back an RSA-2048 encryption key, Bitcoin wallet address and the ransom price in Bitcoins and USD. The information received from the server will be saved into %AppData%\Roaming\cl folder as btc_address.txt, btc_price.txt, public_key.txt, and usd_price.txt.
In the same folder, the virus saves a list of target file extensions as a filelist.txt file. Every file then gets encrypted using the individual AES-256 key generated for each file, then the list of files and their decryption keys gets saved in a new file in CL folder. The file then gets encrypted with the RSA-2048 key.
Once this is done, the ransomware creates How Decrypt My Files.lnk file that automatically executes an index.html file from the How_Decrypt_My_Files folder, which we mentioned earlier. This file contains a full tutorial on how to restore encrypted files. Finally, the ransomware launches a lock screen, which is actually a UI.exe file.
The program keeps checking if the ransom amount was paid and restores files right after the C&C server confirms that the ransom was transmitted. However, the current version of this virus does not delete original file copies. Therefore all you have to do is to delete the virus using a powerful malware removal software. To remove PyCL ransomware the easy way, use programs like FortectIntego. Please do not try to initiate PyCL removal manually – you can do more harm than good to your computer!
Techniques that virus' developers use for its distribution
It is believed that the described ransomware is going to be improved in the nearest future and victims won’ be able to access original file copies anymore. Until then, you should get to know methods used to distribute the virus and what can be done to avoid PyCL ransomware attack.
First of all, malware researchers have discovered that the malicious ransomware was distributed via EITest to RIG exploit kit[5]. However, the ransomware was pushed for the victims only for one day, which gives a warning sign that it was the test of the ransomware. It seems that victims were experiencing redirects after visiting compromised websites, and these redirects would throw them on sites that host RIG EK.
As you might know, exploit kits scan the computer system for vulnerabilities and use them to execute commands on the system. The malicious program steps in as a bogus NSIS installer.
However, this might not be the only distribution method used by cyber criminals – most likely they are going to spread the virus via mail spam. To protect yourself from ransomware attacks, we highly suggest using a strong anti-malware software. Dieviren.de[6] experts suggest using anti-malware and not antivirus program because such software can detect and remove a broader range of malicious programs.
Remove PyCl virus from your PC and recover lost data
To successfully remove PyCL virus and all files it dropped on your system, perform a system check with a security program and let it wipe the ransomware elements from the computer automatically. We do not suggest you try to delete the virus manually because it is simply a very hard thing to do.
This ransomware won’t leave its uninstaller for you, and it means that you need to have certain computing skills in order to complete PyCL removal by yourself. We suggest you a better option – use these instructions given below and delete the virus in automated way.
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