A new mutation of ransomware, which asks for reactivation of Windows, has been reported by F-secure. The user gets a blue screen, saying that the Windows license has been locked. The message screen exactly looks like the Windows screen during installation of OS. There is even a Windows logo on the top-right corner of the screen, to make the message look authentic.
It then prompts the victim to complete activation by calling one of the numbers listed on the screen and get a code. It even says that the phone call is free of charge. However, the call is not free and the victim is charged a hefty bill for the call. The hacker is paid for the call via a technique called short stopping, which involves rogue phone operators routing expensive calls to cheaper countries.
The victim is given the unlock code after 3 minutes of waiting on the call. The unlock code is found out to be 1351236 always. So, the victims can directly use this code number to unlock their PCs without calling the phone numbers.