I wonder how they hide the encryption key in their code, so that nobody can extract it... 
CTB-Locker renames your files with 6 or 7 letters after the original file extension (example: table.xls.srbcgxz). That "srbcgxz" is actually your "ticket" for the line of people who are willing to pay the ransom and it gives you unique unlock key which is about 3 times longer that normal Windows serial number. I saw that you can buy the kit for like $3,000. I wonder what can happen if some antivirus company decide to buy the kit and crack the code.
Just pay the ransom. Problem solved.
Unfortunately currently this is the only way (if you don't have backup).
